Mihalik, J P; Lynall, R C; Wasserman, E B; Guskiewicz, K M; Marshall, S W
Evaluating the "threshold Theory": Can Head Impact Indicators Help? Journal Article
In: Medicine & Science in Sports & Exercise, vol. 49, no. 2, pp. 247–253, 2017.
Abstract | Links | BibTeX | Tags: Biomechanics, Brain Injury, Concussion, sport injury
@article{Mihalik2017,
title = {Evaluating the "threshold Theory": Can Head Impact Indicators Help?},
author = {Mihalik, J P and Lynall, R C and Wasserman, E B and Guskiewicz, K M and Marshall, S W},
doi = {10.1249/MSS.0000000000001089},
year = {2017},
date = {2017-01-01},
journal = {Medicine \& Science in Sports \& Exercise},
volume = {49},
number = {2},
pages = {247--253},
abstract = {Purpose This study aimed to determine the clinical utility of biomechanical head impact indicators by measuring the sensitivity, specificity, positive predictive value (PV+), and negative predictive value (PV-) of multiple thresholds. Methods Head impact biomechanics (n = 283,348) from 185 football players in one Division I program were collected. A multidisciplinary clinical team independently made concussion diagnoses (n = 24). We dichotomized each impact using diagnosis (yes = 24},
keywords = {Biomechanics, Brain Injury, Concussion, sport injury},
pubstate = {published},
tppubtype = {article}
}
Cobb, B R; Zadnik, A M; Rowson, S
Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 50–60, 2016.
Abstract | Links | BibTeX | Tags: Acceleration, Accident prevention, Angular acceleration, Biomechanics, Brain Injury, Coefficient of variation values, Comparative analysis, Concussion, Equipment, Evaluation protocol, helmet testing, Linear acceleration, Linear accelerations, Rotational acceleration, Safety devices, Sporting goods, standards
@article{Cobb2016,
title = {Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms},
author = {Cobb, B R and Zadnik, A M and Rowson, S},
doi = {10.1177/1754337115599133},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology},
volume = {230},
number = {1},
pages = {50--60},
abstract = {As advanced helmet testing methodologies are developed, the effect headform selection may have on the biomechanical impact response must be considered. This study sought to assess response differences between two of the most commonly used headforms, the Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms, through a series of helmeted impact tests. A total of 180 pendulum impact tests were conducted with three impactor velocities and six impact locations. Test condition-specific significant differences were found between the two headforms for peak linear and angular accelerations ($alpha$ = 0.05), although differences tended to be small. On average, the National Operating Committee on Standards for Athletic Equipment headform experienced higher peak linear (3.7 ± 7.8%) and angular (12.0 ± 21.6%) accelerations, with some of the largest differences associated with impacts to the facemask. Without the facemask impacts, the average differences in linear (1.8 ± 6.0%) and angular (9.6 ± 15.9%) acceleration would be lower. No significant differences were found in coefficient of variation values for linear (Hybrid III: 2.6 ± 2.3%, National Operating Committee on Standards for Athletic Equipment: 2.0 ± 1.4%) or angular (Hybrid III: 4.9 ± 4.0%; National Operating Committee on Standards for Athletic Equipment: 5.2 ± 5.8%) acceleration. These data have application toward development and validation of future helmet evaluation protocols and standards. © IMechE 2015.},
keywords = {Acceleration, Accident prevention, Angular acceleration, Biomechanics, Brain Injury, Coefficient of variation values, Comparative analysis, Concussion, Equipment, Evaluation protocol, helmet testing, Linear acceleration, Linear accelerations, Rotational acceleration, Safety devices, Sporting goods, standards},
pubstate = {published},
tppubtype = {article}
}
Gilchrist, I; Moglo, K; Storr, M; Pelland, L
Effects of head flexion posture on the multidirectional static force capacity of the neck Journal Article
In: Clinical Biomechanics, vol. 37, pp. 44–52, 2016.
Abstract | Links | BibTeX | Tags: adult, Article, Biomechanics, BIOPHYSICS, body equilibrium, body posture, Cervical spine, Concussions, contact sport, cross-sectional study, Dynamometry, force, head flexion, head movement, head position, human, human experiment, Male, Muscle, muscle contraction, muscle strength, neck injury, Neck muscle, neck strength, priority journal
@article{Gilchrist2016,
title = {Effects of head flexion posture on the multidirectional static force capacity of the neck},
author = {Gilchrist, I and Moglo, K and Storr, M and Pelland, L},
doi = {10.1016/j.clinbiomech.2016.05.016},
year = {2016},
date = {2016-01-01},
journal = {Clinical Biomechanics},
volume = {37},
pages = {44--52},
abstract = {Background Neck muscle force protects vertebral alignment and resists potentially injurious loading of osteoligamentous structures during head impacts. As the majority of neck muscles generate moments about all three planes of motion, it is not clear how the force capacity of the neck might be modulated by direction of force application and head posture. The aim of our study was to measure the multidirectional moment-generating capacity of the neck and to evaluate effects of 20° of head flexion, a common head position in contact sports, on the measured capacity. Methods We conducted a cross-sectional study, with 25 males, 20-30 years old, performing maximum voluntary contractions, with ballistic intent, along eight directions, set at 45° intervals in the horizontal plane of the head. Three-dimensional moments at C3 and T1 were calculated using equations of static equilibrium. The variable of interest was the impulse of force generated from 0-50 ms. Effects of direction of force application and head posture, neutral and 20° flexion, were evaluated by two-way analysis of variance and linear regression. Findings Impulse of force was lower along diagonal planes, at 45° from the mid-sagittal plane, compared to orthogonal planes (P \< 0.001). Compared to neutral posture, head flexion produced a 55.2% decrease in impulse capacity at C3 and 45.9% at T1. Interpretation The risk of injury with head impact would intrinsically be higher along diagonal planes and with a 20° head down position due to a lower moment generating capacity of the neck in the first 50 ms of force application. © 2015 Elsevier Ltd. All rights reserved.},
keywords = {adult, Article, Biomechanics, BIOPHYSICS, body equilibrium, body posture, Cervical spine, Concussions, contact sport, cross-sectional study, Dynamometry, force, head flexion, head movement, head position, human, human experiment, Male, Muscle, muscle contraction, muscle strength, neck injury, Neck muscle, neck strength, priority journal},
pubstate = {published},
tppubtype = {article}
}
Herman, D C; Barth, J T
Drop-jump landing varies with baseline neurocognition: Implications for anterior cruciate ligament injury risk and prevention Journal Article
In: American Journal of Sports Medicine, vol. 44, no. 9, pp. 2347–2353, 2016.
Abstract | Links | BibTeX | Tags: ACL, Biomechanics, Injury prevention, Motion analysis
@article{Herman2016,
title = {Drop-jump landing varies with baseline neurocognition: Implications for anterior cruciate ligament injury risk and prevention},
author = {Herman, D C and Barth, J T},
doi = {10.1177/0363546516657338},
year = {2016},
date = {2016-01-01},
journal = {American Journal of Sports Medicine},
volume = {44},
number = {9},
pages = {2347--2353},
abstract = {Background: Neurocognitive status may be a risk factor for anterior cruciate ligament (ACL) injury. Neurocognitive domains such as visual attention, processing speed/reaction time, and dual-tasking may influence ACL injury risk via alterations to neuromuscular performance during athletic tasks. However, the relationship between neurocognition and performance during athletic tasks is not yet established. Hypothesis: Athletes with low baseline neurocognitive scores will demonstrate poorer jump landing performance compared with athletes with high baseline neurocognitive score. Study Design: Controlled laboratory study. Methods: Neurocognitive performance was measured using the Concussion Resolution Index (CRI). Three-dimensional kinematic and kinetic data of the dominant limb were collected for 37 recreational athletes while performing an unanticipated jump-landing task. Healthy, nonconcussed subjects were screened using a computer-based neurocognitive test into a high performers (HP; n = 20; average CRI percentile, 78th) and a low performers (LP; n = 17; average CRI percentile, 41st) group. The task consisted of a forward jump onto a force plate with an immediate rebound to a second target that was assigned 250 milliseconds before landing on the force plate. Kinematic and kinetic data were obtained during the first jump landing. Results: The LP group demonstrated significantly altered neuromuscular performance during the landing phase while completing the jump-landing task, including significantly increased peak vertical ground-reaction force (mean ± SD of LP vs HP: 1.81 ± 0.53 vs 1.38 ± 0.37 body weight [BW]; P \<.01), peak anterior tibial shear force (0.91 ± 0.17 vs 0.72 ± 0.22 BW; P \<.01), knee abduction moment (0.47 ± 0.56 vs 0.03 ± 0.64 BW × body height; P =.03), and knee abduction angle (6.1° ± 4.7° vs 1.3° ± 5.6°; P =.03), as well as decreased trunk flexion angle (9.6° ± 9.6° vs 16.4° ± 11.2°; P \<.01). Conclusion: Healthy athletes with lower baseline neurocognitive performance generate knee kinematic and kinetic patterns that are linked to ACL injury. Clinical Relevance: Neurocognitive testing using the CRI may be useful for identification of athletes at elevated risk for future ACL injury. © American Orthopaedic Society for Sports Medicine.},
keywords = {ACL, Biomechanics, Injury prevention, Motion analysis},
pubstate = {published},
tppubtype = {article}
}
Muise, D P; MacKenzie, S J; Sutherland, T M
Frequency and magnitude of head accelerations in a Canadian interuniversity sport football team’s training camp and season Journal Article
In: International Journal of Athletic Therapy & Training, vol. 21, no. 5, pp. 36–41, 2016.
Abstract | Links | BibTeX | Tags: Biomechanics, Concussion, mTBI, Sport
@article{Muise2016,
title = {Frequency and magnitude of head accelerations in a Canadian interuniversity sport football team’s training camp and season},
author = {Muise, D P and MacKenzie, S J and Sutherland, T M},
doi = {10.1123/ijatt.2016-0005},
year = {2016},
date = {2016-01-01},
journal = {International Journal of Athletic Therapy \& Training},
volume = {21},
number = {5},
pages = {36--41},
abstract = {The increased awareness of concussion in sport has led to an examination of head impacts and the associated biomechanics that occur during these sporting events. The high rate of concussions in football makes it particularly relevant.1 The purpose of this study was to examine how frequently, and to what magnitude, Canadian University football players get hit in training camp and how this compares to practices and games in regular season. An ANOVA with repeated measures indicated that, on average, players were hit significantly more in games (45.2 hits) than training camp sessions (17.7 hits) and practices (8.0 hits), while training camp was associated with significantly more hits than practices (p \<. 001, $eta$2 =.392). Multiple positional differences were found. In particular, significantly more hits were experienced by offensive linemen (36.7 hits) and defensive linemen (31.6 hits) compared with all other positions (p \<.001, $eta$2 =.247). Study outcomes determined players/positions most at risk for concussion due to head impacts, which is beneficial in forming concussion prevention and assessment strategies. © 2016 Human Kinetics \textendashIJATT.},
keywords = {Biomechanics, Concussion, mTBI, Sport},
pubstate = {published},
tppubtype = {article}
}
O'Sullivan, D; Fife, G P; Pieter, W; Lim, T; Shin, I
Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks Journal Article
In: Journal of Sport and Health Science, vol. 5, no. 2, pp. 226–230, 2016.
Abstract | Links | BibTeX | Tags: accelerometer, Adolescent, age distribution, analytical parameters, Article, athlete, Biomechanics, body mass, Concussion, controlled study, head injury, high school student, human, injury, Male, Martial Arts, middle school student, priority journal, resultant linear acceleration, taekwondo, university student
@article{OSullivan2016,
title = {Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks},
author = {O'Sullivan, D and Fife, G P and Pieter, W and Lim, T and Shin, I},
doi = {10.1016/j.jshs.2015.01.004},
year = {2016},
date = {2016-01-01},
journal = {Journal of Sport and Health Science},
volume = {5},
number = {2},
pages = {226--230},
abstract = {Objective: The purpose of this study was to compare the effects of various taekwondo kicks and age (school level) in absolute terms and relative body mass on the resultant linear acceleration (RLA) of an instrumented head form. Methods: Forty-eight male (middle school: 16; high school: 16; university: 16) taekwondo athletes were recruited for this study. Subjects performed 10 turning, 10 jump spinning hook, and 10 jump back kicks on a Hybrid II head mounted on a height-adjustable frame. Results: A 2-way (School × Kick) MANOVA was used to determine the differences in RLA between schools (age groups) by type of kick. There was no univariate School main effect for absolute RLA ($eta$2 = 0.06) and RLA relative to body mass ($eta$2 = 0.06). No univariate Kick main effects were found for absolute ($eta$2 = 0.06) and relative RLA ($eta$2 = 0.06). Conclusion: It is of concern that RLA did not significantly differ between school levels, implying that young taekwondo athletes generate similar forces to their adult counterparts, possibly exposing young athletes to an increased risk for head injuries. © 2016.},
keywords = {accelerometer, Adolescent, age distribution, analytical parameters, Article, athlete, Biomechanics, body mass, Concussion, controlled study, head injury, high school student, human, injury, Male, Martial Arts, middle school student, priority journal, resultant linear acceleration, taekwondo, university student},
pubstate = {published},
tppubtype = {article}
}
Patton, D A; McIntosh, A S
Considerations for the performance requirements and technical specifications of soft-shell padded headgear Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 29–42, 2016.
Abstract | Links | BibTeX | Tags: Australian football, Biomechanics, Concussion, Design, Head Injuries, head injury, headgear, Injury prevention, protective equipment, rugby, Sports
@article{Patton2016b,
title = {Considerations for the performance requirements and technical specifications of soft-shell padded headgear},
author = {Patton, D A and McIntosh, A S},
doi = {10.1177/1754337115615482},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology},
volume = {230},
number = {1},
pages = {29--42},
abstract = {Laboratory and epidemiological research in Australian football, rugby league and rugby union has demonstrated that commercially available soft-shell padded headgear is currently ineffective in reducing the risk of concussion. However, modified headgear studies have demonstrated that significant improvements in impact energy attenuation performance are possible with small design changes, such as increases in foam density and thickness. A literature review of the design, performance and use of headgear in Australian football, rugby league and rugby union was conducted. A total of 23 articles were identified using primary and secondary search strategies, which included epidemiological field studies, laboratory impact test studies and studies investigating the behaviours and attitudes of players. The results of the review were synthesised and used to identify injury reduction objectives and appropriate design criteria. The need for a headgear standard was identified and performance requirements were discussed, which drew upon human tolerance and sports-specific head impact exposure data. Usability and behavioural issues, which require consideration during the design process, were also assessed. © IMechE 2015.},
keywords = {Australian football, Biomechanics, Concussion, Design, Head Injuries, head injury, headgear, Injury prevention, protective equipment, rugby, Sports},
pubstate = {published},
tppubtype = {article}
}
schmidtj uga edu Schmidt, Julianne D; Guskiewicz, Kevin M; Mihalik, Jason P; Blackburn, J Troy; Siegmund, Gunter P; Marshall, Stephen W
Head Impact Magnitude in American High School Football Journal Article
In: Pediatrics, vol. 138, no. 2, pp. 1–9, 2016, ISBN: 00314005.
Abstract | Links | BibTeX | Tags: ACCELERATION (Mechanics), Biomechanics, DATA analysis -- Software, Football injuries -- Prevention, Head injuries -- Prevention, HIGH school athletes, SAFETY hats, SAMPLING (Statistics), VIDEO recording
@article{Schmidt2016,
title = {Head Impact Magnitude in American High School Football},
author = {schmidtj uga edu Schmidt, Julianne D and Guskiewicz, Kevin M and Mihalik, Jason P and Blackburn, J Troy and Siegmund, Gunter P and Marshall, Stephen W},
doi = {10.1542/peds.2015-4231},
isbn = {00314005},
year = {2016},
date = {2016-01-01},
journal = {Pediatrics},
volume = {138},
number = {2},
pages = {1--9},
abstract = {OBJECTIVES: To describe determinants of head impact magnitudes between various play aspects in high school football. METHODS: Thirty-two high school American football players wore Head Impact Telemetry System instrumented helmets to capture head impact magnitude (linear acceleration, rotational acceleration, and Head Impact Technology severity profile [HITsp]). We captured and analyzed video from 13 games (n = 3888 viewable head impacts) to determine the following play aspects: quarter, impact cause, play type, closing distance, double head impact, player's stance, player's action, direction of gaze, athletic readiness, level of anticipation, player stationary, ball possession, receiving ball, and snapping ball. We conducted random intercepts general linear mixed models to assess the differences in head impact magnitude between play aspects ($alpha$ = 0.05). RESULTS: The following aspects resulted in greater head impact magnitude: impacts during the second quarter (HITsp: P= .03); contact with another player (linear, rotational, HITsp: P \< .001); initial head impact when the head is struck twice (linear, rotational, HITsp: P \< .001); longer closing distances, especially when combined with a 3-point stance or when being struck in the head (linear: P = .03); the 2-point stance (linear, rotational, HITsp: P \< .001); and offensive linemen not snapping the ball compared with those snapping the ball (rotational: P = .02, HITsp: P = .02). CONCLUSIONS: Preventing head impacts caused by contact with another player may reduce head impact magnitude in high school football. Rule or coaching changes that reduce collisions after long closing distances, especially when combined with the 3-point stance or when a player is being struck in the head, should be considered. [ABSTRACT FROM AUTHOR]},
keywords = {ACCELERATION (Mechanics), Biomechanics, DATA analysis -- Software, Football injuries -- Prevention, Head injuries -- Prevention, HIGH school athletes, SAFETY hats, SAMPLING (Statistics), VIDEO recording},
pubstate = {published},
tppubtype = {article}
}
Caccese, J B; Buckley, T A; Kaminski, T W
Sway area and velocity correlated with MobileMat Balance Error Scoring System (BESS) scores Journal Article
In: Journal of Applied Biomechanics, vol. 32, no. 4, pp. 329–334, 2016.
Abstract | Links | BibTeX | Tags: Approximate entropy, Balance, Balancing, Biomechanics, BIOPHYSICS, Concussion, Entropy, Linear measures, Nonlinear measure, ORTHOPEDICS, Outcome measures, postural stability, Sample entropy, Scoring systems
@article{Caccese2016,
title = {Sway area and velocity correlated with MobileMat Balance Error Scoring System (BESS) scores},
author = {Caccese, J B and Buckley, T A and Kaminski, T W},
doi = {10.1123/jab.2015-0273},
year = {2016},
date = {2016-01-01},
journal = {Journal of Applied Biomechanics},
volume = {32},
number = {4},
pages = {329--334},
abstract = {The Balance Error Scoring System (BESS) is often used for sport-related concussion balance assessment. However, moderate intratester and intertester reliability may cause low initial sensitivity, suggesting that a more objective balance assessment method is needed. The MobileMat BESS was designed for objective BESS scoring, but the outcome measures must be validated with reliable balance measures. Thus, the purpose of this investigation was to compare MobileMat BESS scores to linear and nonlinear measures of balance. Eighty-eight healthy collegiate student-athletes (age: 20.0 ± 1.4 y, height: 177.7 ± 10.7 cm, mass: 74.8 ± 13.7 kg) completed the MobileMat BESS. MobileMat BESS scores were compared with 95% area, sway velocity, approximate entropy, and sample entropy. MobileMat BESS scores were significantly correlated with 95% area for single-leg (r =.332) and tandem firm (r =.474), and double-leg foam (r =.660); and with sway velocity for single-leg (r =.406) and tandem firm (r =.601), and double-leg (r =.575) and single-leg foam (r =.434). MobileMat BESS scores were not correlated with approximate or sample entropy. MobileMat BESS scores were low to moderately correlated with linear measures, suggesting the ability to identify changes in the center of mass-center of pressure relationship, but not higher-order processing associated with nonlinear measures. These results suggest that the MobileMat BESS may be a clinically-useful tool that provides objective linear balance measures. © 2016 Human Kinetics, Inc.},
keywords = {Approximate entropy, Balance, Balancing, Biomechanics, BIOPHYSICS, Concussion, Entropy, Linear measures, Nonlinear measure, ORTHOPEDICS, Outcome measures, postural stability, Sample entropy, Scoring systems},
pubstate = {published},
tppubtype = {article}
}
Herman, Daniel C; Zaremski, Jason L; Vincent, Heather K; Vincent, Kevin R
Effect of neurocognition and concussion on musculoskeletal injury risk Journal Article
In: Current Sports Medicine Reports, vol. 14, pp. 194–199, 2015, ISSN: 1537-890X.
Links | BibTeX | Tags: Biomechanics
@article{Herman2015,
title = {Effect of neurocognition and concussion on musculoskeletal injury risk},
author = {Herman, Daniel C and Zaremski, Jason L and Vincent, Heather K and Vincent, Kevin R},
doi = {10.1249/JSR.0000000000000157},
issn = {1537-890X},
year = {2015},
date = {2015-01-01},
journal = {Current Sports Medicine Reports},
volume = {14},
pages = {194--199},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Post, A; Blaine Hoshizaki, T
Rotational acceleration, brain tissue strain, and the relationship to concussion Journal Article
In: Journal of Biomechanical Engineering, vol. 137, pp. 1, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Post2015c,
title = {Rotational acceleration, brain tissue strain, and the relationship to concussion},
author = {Post, A and {Blaine Hoshizaki}, T},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {137},
pages = {1},
abstract = {The mechanisms of concussion have been investigated by many researchers using a variety of methods. However, there remains much debate over the relationships between head kinematics from an impact and concussion. This review presents the links between research conducted in different disciplines to better understand the relationship between linear and rotational acceleration and brain strains that have been postulated as the root cause of concussion. These concepts are important when assigning performance variables for helmet development, car design, and protective innovation research.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Tong, D C; Winter, T J; Jin, J; Bennett, A C; Waddell, J N
Quantification of subconcussive impact forces to the head using a forensic model Journal Article
In: Journal of Clinical Neuroscience, vol. 22, pp. 747–751, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Tong2015,
title = {Quantification of subconcussive impact forces to the head using a forensic model},
author = {Tong, D C and Winter, T J and Jin, J and Bennett, A C and Waddell, J N},
year = {2015},
date = {2015-01-01},
journal = {Journal of Clinical Neuroscience},
volume = {22},
pages = {747--751},
address = {Tong,D C. Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin 9010, New Zealand. Electronic address: darryl.tong@otago.ac.nz. Winter,T J. Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dun},
abstract = {Concussive and subconcussive head injury is a global phenomenon that affects millions of people each year. Concussive injury has been extensively studied in sport, which has led to a greater understanding of the biomechanical forces involved and guidelines aimed at preventing athletes from playing while concussed. Subconcussive forces by definition do not meet the threshold for concussion but nonetheless may have significant long term consequences due to the repetitive pattern of injury to the head. Quantifying these impact forces using a forensic head model provides the groundwork for future studies by establishing a range or threshold of subconcussive impact forces that could be correlated with clinical assessments. The use of a forensic head model has distinct advantages in terms of ethics and safety.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Iraji, A; Benson, R R; Welch, R D; O'Neil, B J; Woodard, J L; Ayaz, S I; Kulek, A; Mika, V; Medado, P; Soltanian-Zadeh, H; Liu, T; Haacke, E M; Kou, Z
Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 1031–1045, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Iraji2015,
title = {Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses},
author = {Iraji, A and Benson, R R and Welch, R D and O'Neil, B J and Woodard, J L and Ayaz, S I and Kulek, A and Mika, V and Medado, P and Soltanian-Zadeh, H and Liu, T and Haacke, E M and Kou, Z},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {1031--1045},
address = {Iraji,Armin. 1 Department of Biomedical Engineering, Wayne State University , Detroit, Michigan. Benson,Randall R. 2 Center for Neurologic Studies , Novi, Michigan. Welch,Robert D. 3 Department of Emergency Medicine, Wayne State University , Detroit, Mich},
abstract = {Mild traumatic brain injury (mTBI) accounts for more than 1 million emergency visits each year. Most of the injured stay in the emergency department for a few hours and are discharged home without a specific follow-up plan because of their negative clinical structural imaging. Advanced magnetic resonance imaging (MRI), particularly functional MRI (fMRI), has been reported as being sensitive to functional disturbances after brain injury. In this study, a cohort of 12 patients with mTBI were prospectively recruited from the emergency department of our local Level-1 trauma center for an advanced MRI scan at the acute stage. Sixteen age- and sex-matched controls were also recruited for comparison. Both group-based and individual-based independent component analysis of resting-state fMRI (rsfMRI) demonstrated reduced functional connectivity in both posterior cingulate cortex (PCC) and precuneus regions in comparison with controls, which is part of the default mode network (DMN). Further seed-based analysis confirmed reduced functional connectivity in these two regions and also demonstrated increased connectivity between these regions and other regions of the brain in mTBI. Seed-based analysis using the thalamus, hippocampus, and amygdala regions further demonstrated increased functional connectivity between these regions and other regions of the brain, particularly in the frontal lobe, in mTBI. Our data demonstrate alterations of multiple brain networks at the resting state, particularly increased functional connectivity in the frontal lobe, in response to brain concussion at the acute stage. Resting-state functional connectivity of the DMN could serve as a potential biomarker for improved detection of mTBI in the acute setting.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Ji, S; Zhao, W
A Pre-computed Brain Response Atlas for Instantaneous Strain Estimation in Contact Sports Journal Article
In: Annals of Biomedical Engineering, vol. 43, pp. 1877–1895, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Ji2015,
title = {A Pre-computed Brain Response Atlas for Instantaneous Strain Estimation in Contact Sports},
author = {Ji, S and Zhao, W},
year = {2015},
date = {2015-01-01},
journal = {Annals of Biomedical Engineering},
volume = {43},
pages = {1877--1895},
address = {Ji,Songbai. Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA, Songbai.Ji@Dartmouth.edu.},
abstract = {Finite element models of the human head play an important role in investigating the mechanisms of traumatic brain injury, including sports concussion. A critical limitation, however, is that they incur a substantial computational cost to simulate even a single impact. Therefore, current simulation schemes significantly hamper brain injury studies based on model-estimated tissue-level responses. In this study, we present a pre-computed brain response atlas (pcBRA) to substantially increase the simulation efficiency in estimating brain strains using isolated rotational acceleration impulses parameterized with four independent variables (peak magnitude and duration, and rotational axis azimuth and elevation angles) with values determined from on-field measurements. Using randomly generated testing datasets, the partially established pcBRA achieved a 100% success rate in interpolation based on element-wise differences in accumulated peak strain ([Formula: see text]) according to a "double-10%" criterion or average regional [Formula: see text] in generic regions and the corpus callosum. A similar performance was maintained in extrapolation. The pcBRA performance was further successfully validated against directly simulated responses from two independently measured typical real-world rotational profiles. The computational cost to estimate element-wise whole-brain or regional [Formula: see text] was 6 s and \<0.01 s, respectively, vs. $sim$50 min directly simulating a 40 ms impulse. These findings suggest the pcBRA could substantially increase the throughput in impact simulation without significant loss of accuracy from the estimation itself and, thus, its potential to accelerate the exploration of the mechanisms of sports concussion in general. If successful, the pcBRA may also become a diagnostic adjunct in conjunction with sensors that measure head impact kinematics on the field to objectively monitor and identify tissue-level brain trauma in real-time for "return-to-play" decision-making on the sideline.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Post, A; Kendall, M; Koncan, D; Cournoyer, J; Blaine Hoshizaki, T; Gilchrist, M D; Brien, S; Cusimano, M D; Marshall, S
Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling Journal Article
In: Journal of the Mechanical Behavior of Biomedical Materials, vol. 41, pp. 325–335, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Post2015,
title = {Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling},
author = {Post, A and Kendall, M and Koncan, D and Cournoyer, J and {Blaine Hoshizaki}, T and Gilchrist, M D and Brien, S and Cusimano, M D and Marshall, S},
year = {2015},
date = {2015-01-01},
journal = {Journal of the Mechanical Behavior of Biomedical Materials},
volume = {41},
pages = {325--335},
address = {Post,Andrew. Human Kinetics, University of Ottawa, Ottawa, ON, Canada K1N 6N5. Electronic address: apost@uottawa.ca. Kendall,Marshall. Human Kinetics, University of Ottawa, Ottawa, ON, Canada K1N 6N5. Koncan,David. Human Kinetics, University of Ottawa, Ot},
abstract = {Concussions occur 1.7 million times a year in North America, and account for approximately 75% of all traumatic brain injuries (TBI). Concussions usually cause transient symptoms but 10 to 20% of patients can have symptoms that persist longer than a month. The purpose of this research was to use reconstructions and finite element modeling to determine the brain tissue stresses and strains that occur in impacts that led to persistent post concussive symptoms (PCS) in hospitalized patients. A total of 21 PCS patients had their head impacts reconstructed using computational, physical and finite element methods. The dependent variables measured were maximum principal strain, von Mises stress (VMS), strain rate, and product of strain and strain rate. For maximum principal strain alone there were large regions of brain tissue incurring 30 to 40% strain. This large field of strain was also evident when using strain rate, product of strain and strain rate. In addition, VMS also showed large magnitudes of stress throughout the cerebrum tissues. The distribution of strains throughout the brain tissues indicated peak responses were always present in the grey matter (0.481), with the white matter showing significantly lower strains (0.380) (p\<0.05). The impact conditions of the PCS cases were severe in nature, with impacts against non-compliant surfaces (concrete, steel, ice) resulting in higher brain deformation. PCS biomechanical parameters were shown to fit between those that have been shown to cause transient post concussive symptoms and those that lead to actual pathologic damage like contusion, however, values of all metrics were characterized by large variance and high average responses. This data supports the theory that there exists a progressive continuum of impacts that lead to a progressive continuum of related severity of injury from transient symptoms to pathological damage.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Meier, T B; Bellgowan, P S; Singh, R; Kuplicki, R; Polanski, D W; Mayer, A R
Recovery of cerebral blood flow following sports-related concussion Journal Article
In: JAMA Neurology, vol. 72, pp. 530–538, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Meier2015,
title = {Recovery of cerebral blood flow following sports-related concussion},
author = {Meier, T B and Bellgowan, P S and Singh, R and Kuplicki, R and Polanski, D W and Mayer, A R},
year = {2015},
date = {2015-01-01},
journal = {JAMA Neurology},
volume = {72},
pages = {530--538},
address = {Meier,Timothy B. The Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico2Laureate Institute for Brain Research, Tulsa, Oklahoma. Bellgowan,Patrick S F. Laureate Institute for Brain Research, Tulsa, Oklah},
abstract = {IMPORTANCE: Animal models suggest that reduced cerebral blood flow (CBF) is one of the most enduring physiological deficits following concussion. Despite this, longitudinal studies documenting serial changes in regional CBF following human concussion have yet to be performed. OBJECTIVE: To longitudinally assess the recovery of CBF in a carefully selected sample of collegiate athletes and compare time course of CBF recovery with that of cognitive and behavioral symptoms. DESIGN, SETTING, AND PARTICIPANTS: A cohort of collegiate football athletes (N = 44) participated in this mixed longitudinal and cross-sectional study at a private research institute specializing in neuroimaging between March 2012 and December 2013. Serial imaging occurred approximately 1 day, 1 week, and 1 month postconcussion for a subset of participants (n = 17). All athletes reported no premorbid mood disorders, anxiety disorders, substance abuse, or alcohol abuse. MAIN OUTCOMES AND MEASURES: Arterial spin labeling magnetic resonance imaging was used to collect voxelwise relative CBF at each visit. Neuropsychiatric evaluations and a brief cognitive screen were also performed at all 3 points. Clinicians trained in sports medicine provided an independent measure of real-world concussion outcome (ie, number of days withheld from competition). RESULTS: The results indicated both cognitive (simple reaction time) and neuropsychiatric symptoms at 1 day postinjury that resolved at either 1 week (cognitive; P \<.005) or 1 month (neuropsychiatric; P \<.005) postinjury. Imaging data suggested both cross-sectional (ie, healthy vs concussed athletes; P \<.05) and longitudinal (1 day and 1 week vs 1 month postinjury; P \<.001) evidence of CBF recovery in the right insular and superior temporal cortex. Importantly, CBF in the dorsal midinsular cortex was both decreased at 1 month postconcussion in slower-to-recover athletes (t11 = 3.45; P =.005) and was inversely related to the magnitude of initial psychiatric symptoms (Hamilton Depression Scale: r = -0.64},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Kerr, Z Y; Littleton, A C; Cox, L M; DeFreese, J D; Varangis, E; Lynall, R C; Schmidt, J D; Marshall, S W; Guskiewicz, K M
Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 1083–1089, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Kerr2015ab,
title = {Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate},
author = {Kerr, Z Y and Littleton, A C and Cox, L M and DeFreese, J D and Varangis, E and Lynall, R C and Schmidt, J D and Marshall, S W and Guskiewicz, K M},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {1083--1089},
address = {Kerr,Zachary Y. 1 The Datalys Center for Sports Injury Research and Prevention, Indianapolis Indiana. Kerr,Zachary Y. 2 Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, University of North Carolina , Chapel Hill, North Carolina. Kerr,},
abstract = {Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information related to primary position played and participation in games and practice contacts during the pre-season, regular season, and post-season of each year of their high school, college, and professional football careers. Spring football for college was also included. We calculated contact exposure estimates for 64 former football players (n=32 college football only},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Rousseau, P; Hoshizaki, T B
Defining the effective impact mass of elbow and shoulder strikes in ice hockey Journal Article
In: Sports Biomechanics, vol. 14, pp. 57–67, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Rousseau2015,
title = {Defining the effective impact mass of elbow and shoulder strikes in ice hockey},
author = {Rousseau, P and Hoshizaki, T B},
year = {2015},
date = {2015-01-01},
journal = {Sports Biomechanics},
volume = {14},
pages = {57--67},
address = {Rousseau,Philippe. a Neurotrauma Impact Science Laboratory, Faculty of Health Sciences , University of Ottawa , Ottawa , ON , Canada.},
abstract = {Reconstruction of real-life events can be used to investigate the relationship between the mechanical parameters of the impact and concussion risk. Striking mass has typically been approximated as being the mass of the body part coming into contact with the head without accounting for the force applied by the striking athlete. Thus, the purpose of this study was to measure the effective impact mass of three common striking techniques in ice hockey. Fifteen participants were instructed to strike a suspended 50th percentile Hybrid III headform at least three times with their elbow or shoulder. Effective impact mass was calculated by measuring the change in velocity of the player and the headform. Mean effective impact mass for the extended elbow, tucked-in elbow, and shoulder check conditions were 4.8, 3.0, and 12.9 kg, respectively. Peak linear accelerations were lower than the values associated with concussion in American football which could be a reflection of the methodology used in this study as well as inherent differences between both sports.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Crisco, J J; Costa, L; Rich, R; Schwartz, J B; Wilcox, B
Surrogate headform accelerations associated with stick checks in girls' lacrosse Journal Article
In: Journal of Applied Biomechanics, vol. 31, pp. 122–127, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Crisco2015,
title = {Surrogate headform accelerations associated with stick checks in girls' lacrosse},
author = {Crisco, J J and Costa, L and Rich, R and Schwartz, J B and Wilcox, B},
year = {2015},
date = {2015-01-01},
journal = {Journal of Applied Biomechanics},
volume = {31},
pages = {122--127},
address = {Crisco,Joseph J. Bioengineering Laboratory, Department of Orthopaedics, Warren Alpert Medical School of Brown University, and Rhode Island Hospital, Providence, RI.},
abstract = {Girls' lacrosse is fundamentally a different sport than boys' lacrosse, and girls are not required to wear protective headgear. Recent epidemiological studies have found that stick checks are the leading cause of concussion injury in girls' lacrosse. The purpose of this study was to determine stick check speeds and estimate the head acceleration associated with direct checks to the head. In addition, we briefly examine if commercially available headgear can mitigate the accelerations. Seven (n = 7) experienced female lacrosse players checked, with varying severity, a NOSCAE and an ASTM headform. Stick speed at impact and the associated peak linear accelerations of the headform were recorded. The NOCSAE headform was fitted with four commercially available headgear and similar stick impact testing was performed. The median stick impact speed was 8.1 m/s and 777 deg/s. At these speeds, peak linear acceleration was approximately 60g. Three out of the four headgear significantly reduced the peak linear acceleration when compared with the bare headform. These data serve as baseline for understanding the potential mechanism and reduction of concussions from stick impacts in girls' lacrosse.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Oeur, R A; Karton, C; Post, A; Rousseau, P; Hoshizaki, T B; Marshall, S; Brien, S E; Smith, A; Cusimano, M D; Gilchrist, M D
In: Journal of Neurosurgery, vol. 123, no. 2, pp. 415–422, 2015.
Abstract | Links | BibTeX | Tags: accident, Accident reconstruction, accidental injury, Accidents, Adolescent, adult, Article, Biomechanical Phenomena, Biomechanics, brain, brain concussion, brain stem, brain tissue, Cerebellum, clinical article, comparative study, Concussion, controlled study, Female, finite element analysis, Finite element modelling, gray matter, Hematoma, human, Humans, Hybrid iii headform, injury severity, laboratory test, Male, Mechanical, mechanical stress, middle aged, pathology, Pathophysiology, Persistent postconcussive symptoms, PHYSIOLOGY, Post Hoc Analysis, Post-Concussion Syndrome, postconcussion syndrome, priority journal, shear stress, simulation, SPORTS medicine, STATISTICAL significance, Stress, stress strain relationship, Subdural, subdural hematoma, traumatic brain injury, white matter, Young Adult
@article{Oeur2015,
title = {A comparison of head dynamic response and brain tissue stress and strain using accident reconstructions for concussion, concussion with persistent postconcussive symptoms, and subdural hematoma},
author = {Oeur, R A and Karton, C and Post, A and Rousseau, P and Hoshizaki, T B and Marshall, S and Brien, S E and Smith, A and Cusimano, M D and Gilchrist, M D},
doi = {10.3171/2014.10.JNS14440},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurosurgery},
volume = {123},
number = {2},
pages = {415--422},
abstract = {Object Concussions typically resolve within several days, but in a few cases the symptoms last for a month or longer and are termed persistent postconcussive symptoms (PPCS). These persisting symptoms may also be associated with more serious brain trauma similar to subdural hematoma (SDH). The objective of this study was to investigate the head dynamic and brain tissue responses of injury reconstructions resulting in concussion, PPCS, and SDH. Methods Reconstruction cases were obtained from sports medicine clinics and hospitals. All subjects received a direct blow to the head resulting in symptoms. Those symptoms that resolved in 9 days or fewer were defined as concussions (n = 3). Those with symptoms lasting longer than 18 months were defined as PPCS (n = 3), and 3 patients presented with SDHs (n = 3). A Hybrid III headform was used in reconstruction to obtain linear and rotational accelerations of the head. These dynamic response data were then input into the University College Dublin Brain Trauma Model to calculate maximum principal strain and von Mises stress. A Kruskal-Wallis test followed by Tukey post hoc tests were used to compare head dynamic and brain tissue responses between injury groups. Statistical significance was set at p \< 0.05. Results A significant difference was identified for peak resultant linear and rotational acceleration between injury groups. Post hoc analyses revealed the SDH group had higher linear and rotational acceleration responses (316 g and 23,181 rad/sec2, respectively) than the concussion group (149 g and 8111 rad/sec2, respectively; p \< 0.05). No significant differences were found between groups for either brain tissue measures of maximum principal strain or von Mises stress. Conclusions The reconstruction of accidents resulting in a concussion with transient symptoms (low severity) and SDHs revealed a positive relationship between an increase in head dynamic response and the risk for more serious brain injury. This type of relationship was not found for brain tissue stress and strain results derived by finite element analysis. Future research should be undertaken using a larger sample size to confirm these initial findings. Understanding the relationship between the head dynamic and brain tissue response and the nature of the injury provides important information for developing strategies for injury prevention. © AANS, 2015.},
keywords = {accident, Accident reconstruction, accidental injury, Accidents, Adolescent, adult, Article, Biomechanical Phenomena, Biomechanics, brain, brain concussion, brain stem, brain tissue, Cerebellum, clinical article, comparative study, Concussion, controlled study, Female, finite element analysis, Finite element modelling, gray matter, Hematoma, human, Humans, Hybrid iii headform, injury severity, laboratory test, Male, Mechanical, mechanical stress, middle aged, pathology, Pathophysiology, Persistent postconcussive symptoms, PHYSIOLOGY, Post Hoc Analysis, Post-Concussion Syndrome, postconcussion syndrome, priority journal, shear stress, simulation, SPORTS medicine, STATISTICAL significance, Stress, stress strain relationship, Subdural, subdural hematoma, traumatic brain injury, white matter, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Patton, D A; McIntosh, A S; Kleiven, S
In: Journal of Applied Biomechanics, vol. 31, no. 4, pp. 264–268, 2015.
Abstract | Links | BibTeX | Tags: Article, Biomechanics, brain, Brain Injury, brain region, clinical article, Concussion, corpus callosum, Damage detection, evaluation study, finite element analysis, Finite element head models, Finite element method, Finite element simulations, football, gray matter, Head Injuries, head injury, human, Intra-cranial pressure, intracranial pressure, investigative procedures, Maximum principal strain, mesencephalon, Modeling, Models, Numerical reconstruction, Qualitative observations, Sport, sport injury, Sports, Strain and strain rates, Strain rate, Stress, thalamus, Tissue, tissue level
@article{Patton2015,
title = {The biomechanical determinants of concussion: Finite element simulations to investigate tissue-level predictors of injury during sporting impacts to the unprotected head},
author = {Patton, D A and McIntosh, A S and Kleiven, S},
doi = {10.1123/jab.2014-0223},
year = {2015},
date = {2015-01-01},
journal = {Journal of Applied Biomechanics},
volume = {31},
number = {4},
pages = {264--268},
abstract = {Biomechanical studies of concussions have progressed from qualitative observations of head impacts to physical and numerical reconstructions, direct impact measurements, and finite element analyses. Supplementary to a previous study, which investigated maximum principal strain, the current study used a detailed finite element head model to simulate unhelmeted concussion and no-injury head impacts and evaluate the effectiveness of various tissue-level brain injury predictors: strain rate, product of strain and strain rate, cumulative strain damage measure, von Mises stress, and intracranial pressure. Von Mises stress was found to be the most effective predictor of concussion. It was also found that the thalamus and corpus callosum were brain regions with strong associations with concussion. Tentative tolerance limits for tissue-level predictors were proposed in an attempt to broaden the understanding of unhelmeted concussions. For the thalamus, tolerance limits were proposed for a 50% likelihood of concussion: 2.24 kPa, 24.0 s-1, and 2.49 s-1 for von Mises stress, strain rate, and the product of strain and strain rate, respectively. For the corpus callosum, tolerance limits were proposed for a 50% likelihood of concussion: 3.51 kPa, 25.1 s-1, and 2.76 s-1 for von Mises stress, strain rate, and the product of strain and strain rate, respectively. © 2015 Human Kinetics, Inc.},
keywords = {Article, Biomechanics, brain, Brain Injury, brain region, clinical article, Concussion, corpus callosum, Damage detection, evaluation study, finite element analysis, Finite element head models, Finite element method, Finite element simulations, football, gray matter, Head Injuries, head injury, human, Intra-cranial pressure, intracranial pressure, investigative procedures, Maximum principal strain, mesencephalon, Modeling, Models, Numerical reconstruction, Qualitative observations, Sport, sport injury, Sports, Strain and strain rates, Strain rate, Stress, thalamus, Tissue, tissue level},
pubstate = {published},
tppubtype = {article}
}
Zaremski, Jason L; Herman, Daniel C; Clugston, James R; Hurley, Robert W; Ahn, Andrew H
Occipital neuralgia as a sequela of sports concussion: a case series and review of the literature Journal Article
In: Current Sports Medicine Reports, vol. 14, pp. 16–19, 2015, ISSN: 1537-890X.
Links | BibTeX | Tags: Biomechanics
@article{Zaremski2015,
title = {Occipital neuralgia as a sequela of sports concussion: a case series and review of the literature},
author = {Zaremski, Jason L and Herman, Daniel C and Clugston, James R and Hurley, Robert W and Ahn, Andrew H},
doi = {10.1249/JSR.0000000000000121},
issn = {1537-890X},
year = {2015},
date = {2015-01-01},
journal = {Current Sports Medicine Reports},
volume = {14},
pages = {16--19},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Doshi, H; Wiseman, N; Liu, J; Wang, W; Welch, R D; O'Neil, B J; Zuk, C; Wang, X; Mika, V; Szaflarski, J P; Haacke, E M; Kou, Z
Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage Journal Article
In: PLoS ONE, vol. 10, pp. e0118061, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Doshi2015,
title = {Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage},
author = {Doshi, H and Wiseman, N and Liu, J and Wang, W and Welch, R D and O'Neil, B J and Zuk, C and Wang, X and Mika, V and Szaflarski, J P and Haacke, E M and Kou, Z},
year = {2015},
date = {2015-01-01},
journal = {PLoS ONE},
volume = {10},
pages = {e0118061},
address = {Doshi,Hardik. Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America. Wiseman,Natalie. Department of Psychiatry and Behavioral Neurosciences Translational Neuroscience Program, Wayne State University Scho},
abstract = {Mild traumatic brain injury (mTBI) is a significant public health care burden in the United States. However, we lack a detailed understanding of the pathophysiology following mTBI and its relation to symptoms and recovery. With advanced magnetic resonance imaging (MRI), we can investigate brain perfusion and oxygenation in regions known to be implicated in symptoms, including cortical gray matter and subcortical structures. In this study, we assessed 14 mTBI patients and 18 controls with susceptibility weighted imaging and mapping (SWIM) for blood oxygenation quantification. In addition to SWIM, 7 patients and 12 controls had cerebral perfusion measured with arterial spin labeling (ASL). We found increases in regional cerebral blood flow (CBF) in the left striatum, and in frontal and occipital lobes in patients as compared to controls (p = 0.01, 0.03, 0.03 respectively). We also found decreases in venous susceptibility, indicating increases in venous oxygenation, in the left thalamostriate vein and right basal vein of Rosenthal (p = 0.04 in both). mTBI patients had significantly lower delayed recall scores on the standardized assessment of concussion, but neither susceptibility nor CBF measures were found to correlate with symptoms as assessed by neuropsychological testing. The increased CBF combined with increased venous oxygenation suggests an increase in cerebral blood flow that exceeds the oxygen demand of the tissue, in contrast to the regional hypoxia seen in more severe TBI. This may represent a neuroprotective response following mTBI, which warrants further investigation.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Seifert, Tad; Shipman, Victoria
The Pathophysiology of Sports Concussion Journal Article
In: Current Pain & Headache Reports, vol. 19, pp. 513, 2015, ISSN: 1531-3433.
Abstract | Links | BibTeX | Tags: Biomechanics
@article{Seifert2015,
title = {The Pathophysiology of Sports Concussion},
author = {Seifert, Tad and Shipman, Victoria},
doi = {10.1007/s11916-015-0513-0},
issn = {1531-3433},
year = {2015},
date = {2015-01-01},
journal = {Current Pain \& Headache Reports},
volume = {19},
pages = {513},
abstract = {During concussion, the brain is exposed to rapid acceleration, deceleration, and rotational forces, resulting in the stretching and distortion of neural structures. This produces in an injury of transient neurological dysfunction, as evidenced by the clinical symptomatology. It is now evident that recurrent head trauma is also associated with the development of some chronic neurodegenerative disorders. Despite increased awareness of concussion over the past decade, large voids remain in our understanding of its pathophysiology. Prospective longitudinal studies are needed to better understand the underlying biological mechanism of acute concussive injury as it relates to chronic neuropathology.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Pang, K C; Sinha, S; Avcu, P; Roland, J J; Nadpara, N; Pfister, B; Long, M; Santhakumar, V; Servatius, R J
Long-lasting suppression of acoustic startle response after mild traumatic brain injury Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 801–810, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Pang2015,
title = {Long-lasting suppression of acoustic startle response after mild traumatic brain injury},
author = {Pang, K C and Sinha, S and Avcu, P and Roland, J J and Nadpara, N and Pfister, B and Long, M and Santhakumar, V and Servatius, R J},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {801--810},
address = {Pang,Kevin C H. 1Neurobehavioral Research Lab, Department of Veteran Affairs Medical Center-New Jersey Health Care System, East Orange, New Jersey. Pang,Kevin C H. 2Stress and Motivated Behavior Institute, New Jersey Medical School-Rutgers Biomedical and},
abstract = {Acoustic startle response (ASR) is a defensive reflex that is largely ignored unless greatly exaggerated. ASR is suppressed after moderate and severe traumatic brain injury (TBI), but the effect of mild TBI (mTBI) on ASR has not been investigated. Because the neural circuitry for ASR resides in the pons in all mammals, ASR may be a good measure of brainstem function after mTBI. The present study assessed ASR in Sprague-Dawley rats after mTBI using lateral fluid percussion and compared these effects to those on spatial working memory. mTBI caused a profound, long-lasting suppression of ASR. Both probability of emitting a startle and startle amplitude were diminished. ASR suppression was observed as soon as 1 day after injury and remained suppressed for the duration of the study (21 days after injury). No indication of recovery was observed. mTBI also impaired spatial working memory. In contrast to the suppression of ASR, working memory impairment was transient; memory was impaired 1 and 7 days after injury, but recovered by 21 days. The long-lasting suppression of ASR suggests long-term dysfunction of brainstem neural circuits at a time when forebrain neural circuits responsible for spatial working memory have recovered. These results have important implications for return-to-activity decisions because recovery of cognitive impairments plays an important role in these decisions.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Stemper, B D; Shah, A S; Pintar, F A; McCrea, M; Kurpad, S N; Glavaski-Joksimovic, A; Olsen, C; Budde, M D
Head Rotational Acceleration Characteristics Influence Behavioral and Diffusion Tensor Imaging Outcomes Following Concussion Journal Article
In: Annals of Biomedical Engineering, vol. 43, no. 5, pp. 1071–1088, 2015.
Abstract | Links | BibTeX | Tags: Acceleration, Accidents, BEHAVIORAL assessment, Behavioral assessments, Behavioral outcomes, Biomechanics, brain, Cognitive deficits, Diffusion, Diffusion Tensor Imaging, Diffusion tensor imaging (DTI), fractional anisotropy, Full factorial design, Magnetic Resonance Imaging, Microstructure, Motor vehicle crashes, neuroimaging, Rats, Rotational acceleration, Tensors, Traumatic Brain Injuries, Traumatic brain injury (mTBI)
@article{Stemper2015,
title = {Head Rotational Acceleration Characteristics Influence Behavioral and Diffusion Tensor Imaging Outcomes Following Concussion},
author = {Stemper, B D and Shah, A S and Pintar, F A and McCrea, M and Kurpad, S N and Glavaski-Joksimovic, A and Olsen, C and Budde, M D},
doi = {10.1007/s10439-014-1171-9},
year = {2015},
date = {2015-01-01},
journal = {Annals of Biomedical Engineering},
volume = {43},
number = {5},
pages = {1071--1088},
abstract = {A majority of traumatic brain injuries (TBI) in motor vehicle crashes and sporting environments are mild and caused by high-rate acceleration of the head. For injuries caused by rotational acceleration, both magnitude and duration of the acceleration pulse were shown to influence injury outcomes. This study incorporated a unique rodent model of rotational acceleration-induced mild TBI (mTBI) to quantify independent effects of magnitude and duration on behavioral and neuroimaging outcomes. Ninety-two Sprague\textendashDawley rats were exposed to head rotational acceleration at peak magnitudes of 214 or 350 krad/s2 and acceleration pulse durations of 1.6 or 3.4 ms in a full factorial design. Rats underwent a series of behavioral tests including the Composite Neuroscore (CN), Elevated Plus Maze (EPM), and Morris Water Maze (MWM). Ex vivo diffusion tensor imaging (DTI) of the fixed brains was conducted to assess the effects of rotational injury on brain microstructure as revealed by the parameter fractional anisotropy (FA). While the injury did not cause significant locomotor or cognitive deficits measured with the CN and MWM, respectively, a main effect of duration was consistently observed for the EPM. Increased duration caused significantly greater activity and exploratory behaviors measured as open arm time and number of arm changes. DTI demonstrated significant effects of both magnitude and duration, with the FA of the amygdala related to both the magnitude and duration. Increased duration also caused FA changes at the interface of gray and white matter. Collectively, the findings demonstrate that the consequences of rotational acceleration mTBI were more closely associated with duration of the rotational acceleration impulse, which is often neglected as an independent factor, and highlight the need for animal models of TBI with strong biomechanical foundations to associate behavioral outcomes with brain microstructure. © 2014, Biomedical Engineering Society (Outside the U.S.).},
keywords = {Acceleration, Accidents, BEHAVIORAL assessment, Behavioral assessments, Behavioral outcomes, Biomechanics, brain, Cognitive deficits, Diffusion, Diffusion Tensor Imaging, Diffusion tensor imaging (DTI), fractional anisotropy, Full factorial design, Magnetic Resonance Imaging, Microstructure, Motor vehicle crashes, neuroimaging, Rats, Rotational acceleration, Tensors, Traumatic Brain Injuries, Traumatic brain injury (mTBI)},
pubstate = {published},
tppubtype = {article}
}
Franck, J A; Blume, J; Crisco, J J; Franck, C
Extracting Time-Accurate Acceleration Vectors From Nontrivial Accelerometer Arrangements Journal Article
In: Journal of Biomechanical Engineering, vol. 137, pp. 1, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Franck2015,
title = {Extracting Time-Accurate Acceleration Vectors From Nontrivial Accelerometer Arrangements},
author = {Franck, J A and Blume, J and Crisco, J J and Franck, C},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {137},
pages = {1},
abstract = {Sports-related concussions are of significant concern in many impact sports, and their detection relies on accurate measurements of the head kinematics during impact. Among the most prevalent recording technologies are videography, and more recently, the use of single-axis accelerometers mounted in a helmet, such as the HIT system. Successful extraction of the linear and angular impact accelerations depends on an accurate analysis methodology governed by the equations of motion. Current algorithms are able to estimate the magnitude of acceleration and hit location, but make assumptions about the hit orientation and are often limited in the position and/or orientation of the accelerometers. The newly formulated algorithm presented in this manuscript accurately extracts the full linear and rotational acceleration vectors from a broad arrangement of six single-axis accelerometers directly from the governing set of kinematic equations. The new formulation linearizes the nonlinear centripetal acceleration term with a finite-difference approximation and provides a fast and accurate solution for all six components of acceleration over long time periods (\>250ms). The approximation of the nonlinear centripetal acceleration term provides an accurate computation of the rotational velocity as a function of time and allows for reconstruction of a multiple-impact signal. Furthermore, the algorithm determines the impact location and orientation and can distinguish between glancing, high rotational velocity impacts, or direct impacts through the center of mass. Results are shown for ten simulated impact locations on a headform geometry computed with three different accelerometer configurations in varying degrees of signal noise. Since the algorithm does not require simplifications of the actual impacted geometry, the impact vector, or a specific arrangement of accelerometer orientations, it can be easily applied to many impact investigations in which accurate kinematics need to be extracted from single-axis accelerometer data.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Alberts, J L; Hirsch, J R; Koop, M M; Schindler, D D; Kana, D E; Linder, S M; Campbell, S; Thota, A K
Using Accelerometer and Gyroscopic Measures to Quantify Postural Stability Journal Article
In: Journal of Athletic Training, vol. 50, pp. 578–588, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Alberts2015a,
title = {Using Accelerometer and Gyroscopic Measures to Quantify Postural Stability},
author = {Alberts, J L and Hirsch, J R and Koop, M M and Schindler, D D and Kana, D E and Linder, S M and Campbell, S and Thota, A K},
year = {2015},
date = {2015-01-01},
journal = {Journal of Athletic Training},
volume = {50},
pages = {578--588},
address = {Alberts,Jay L. Department of Biomedical Engineering, Cleveland Clinic, OH; Alberts,Jay L. Center for Neurological Restoration, Cleveland Clinic, OH; Alberts,Jay L. Cleveland Clinic Concussion Center, Cleveland Clinic, OH; Alberts,Jay L. Cleveland Function},
abstract = {CONTEXT: Force platforms and 3-dimensional motion-capture systems provide an accurate method of quantifying postural stability. Substantial cost, space, time to administer, and need for trained personnel limit widespread use of biomechanical techniques in the assessment of postural stability in clinical or field environments. OBJECTIVE: To determine whether accelerometer and gyroscope data sampled from a consumer electronics device (iPad2) provide sufficient resolution of center-of-gravity (COG) movements to accurately quantify postural stability in healthy young people. DESIGN: Controlled laboratory study. SETTING: Research laboratory in an academic medical center. PATIENTS OR OTHER PARTICIPANTS: A total of 49 healthy individuals (age = 19.5 +/- 3.1 years},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Giordano, C; Kleiven, S
Evaluation of Axonal Strain as a Predictor for Mild Traumatic Brain Injuries Using Finite Element Modeling Journal Article
In: Stapp Car Crash Journal, vol. 58, pp. 29–61, 2014.
Abstract | BibTeX | Tags: Biomechanics
@article{Giordano2014,
title = {Evaluation of Axonal Strain as a Predictor for Mild Traumatic Brain Injuries Using Finite Element Modeling},
author = {Giordano, C and Kleiven, S},
year = {2014},
date = {2014-01-01},
journal = {Stapp Car Crash Journal},
volume = {58},
pages = {29--61},
address = {Giordano,Chiara. KTH - Royal Institute of Technology, School of Technology and Health, Neuronic Engineering, Alfred Nobels Alle 10, 141 52 Huddinge, Sweden. Kleiven,Svein. KTH - Royal Institute of Technology, School of Technology and Health, Neuronic Engi},
abstract = {Finite element (FE) models are often used to study the biomechanical effects of traumatic brain injury (TBI). Measures based on mechanical responses, such as principal strain or invariants of the strain tensor, are used as a metric to predict the risk of injury. However, the reliability of inferences drawn from these models depends on the correspondence between the mechanical measures and injury data, as well as the establishment of accurate thresholds of tissue injury. In the current study, a validated anisotropic FE model of the human head is used to evaluate the hypothesis that strain in the direction of fibers (axonal strain) is a better predictor of TBI than maximum principal strain (MPS), anisotropic equivalent strain (AESM) and cumulative strain damage measure (CSDM). An analysis of head kinematics-based metrics, such as head injury criterion (HIC) and brain injury criterion (BrIC), is also provided. Logistic regression analysis is employed to compare binary injury data (concussion/no concussion) with continuous strain/kinematics data. The threshold corresponding to 50% of injury probability is determined for each parameter. The predictive power (area under the ROC curve, AUC) is calculated from receiver operating characteristic (ROC) curve analysis. The measure with the highest AUC is considered to be the best predictor of mTBI. Logistic regression shows a statistical correlation between all the mechanical predictors and injury data for different regions of the brain. Peaks of axonal strain have the highest AUC and determine a strain threshold of 0.07 for corpus callosum and 0.15 for the brainstem, in agreement with previously experimentally derived injury thresholds for reversible axonal injury. For a data set of mild TBI from the national football league, the strain in the axonal direction is found to be a better injury predictor than MPS, AESM, CSDM, BrIC and HIC.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Daniel, R W; Rowson, S; Duma, S M
Head acceleration measurements in middle school football Journal Article
In: Biomedical Sciences Instrumentation, vol. 50, pp. 291–296, 2014.
Abstract | BibTeX | Tags: Biomechanics
@article{Daniel2014,
title = {Head acceleration measurements in middle school football},
author = {Daniel, R W and Rowson, S and Duma, S M},
year = {2014},
date = {2014-01-01},
journal = {Biomedical Sciences Instrumentation},
volume = {50},
pages = {291--296},
address = {Daniel,Ray W. Virginia Tech - Wake Forest University, Blacksburg.},
abstract = {Although youth football players account for approximately 70% of all football players, the majority of research investigating concussion in football has focused on adults. The objective of this study was to investigate the head impact exposure experienced by middle school football players between the ages of 12 and 14 years. Recruited players were equipped with helmets instrumented with accelerometer arrays for 5 games and 27 practices. Linear accelerations ranged from 10 g to 150 g and rotational accelerations ranged from 4 rad/s2 to 9019 rad/s2. The average player experienced 210 +/- 162 impacts while instrumented. The average player sustained a median impact of 21 +/- 1 g and 885 +/- 104 rad/s2, and a 95th percentile impact of 57 +/- 12 g and 2570 +/- 544 rad/s2. Data were then used to estimate a full middle school football seasons head impacexposure for comparisons. Both impact magnitude and impact location distributions were similar to past studies investigating head impacts in high school and collegiate football players. Middle school players experience a greater number of impacts during games than during practices, and the majority of impacts occurred to the front or rear of the helmet. With an increased understanding of the head impact exposure experienced by youth football players, measures can be implemented to better protect players.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Duhaime, A C
Response Journal Article
In: Journal of Neurosurgery, vol. 117, no. 6, pp. 1090–1091, 2012, ISBN: 0022-3085 1933-0693.
BibTeX | Tags: Accident prevention, Assessment & Testing, athlete, Biomechanics, brain concussion, Equipment, headache, Helmets, human, Neck pain, neurosurgery, Note, Post-Concussion, priority journal, sport injury, surgeon, symptom, Syndrome, traumatic brain injury, unconsciousness
@article{Duhaime2012,
title = {Response},
author = {Duhaime, A C},
isbn = {0022-3085
1933-0693},
year = {2012},
date = {2012-01-01},
journal = {Journal of Neurosurgery},
volume = {117},
number = {6},
pages = {1090--1091},
keywords = {Accident prevention, Assessment \& Testing, athlete, Biomechanics, brain concussion, Equipment, headache, Helmets, human, Neck pain, neurosurgery, Note, Post-Concussion, priority journal, sport injury, surgeon, symptom, Syndrome, traumatic brain injury, unconsciousness},
pubstate = {published},
tppubtype = {article}
}
Rowson, Steven; Duma, Stefan M; Beckwith, Jonathan G; Chu, Jeffrey J; Greenwald, Richard M; Crisco, Joseph J; Brolinson, P Gunnar; Duhaime, Ann-Christine; McAllister, Thomas W; Maerlender, Arthur C
Rotational head kinematics in football impacts: an injury risk function for concussion Journal Article
In: Annals of Biomedical Engineering, vol. 40, pp. 1–13, 2012.
Abstract | BibTeX | Tags: Biomechanics
@article{Rowson2012,
title = {Rotational head kinematics in football impacts: an injury risk function for concussion},
author = {Rowson, Steven and Duma, Stefan M and Beckwith, Jonathan G and Chu, Jeffrey J and Greenwald, Richard M and Crisco, Joseph J and Brolinson, P Gunnar and Duhaime, Ann-Christine and McAllister, Thomas W and Maerlender, Arthur C},
year = {2012},
date = {2012-01-01},
journal = {Annals of Biomedical Engineering},
volume = {40},
pages = {1--13},
address = {School of Biomedical Engineering \& Sciences, Virginia Tech-Wake Forest University, 440 ICTAS Building, Stanger St, Blacksburg, VA 24061, USA. srowson@vt.edu},
abstract = {Recent research has suggested a possible link between sports-related concussions and neurodegenerative processes, highlighting the importance of developing methods to accurately quantify head impact tolerance. The use of kinematic parameters of the head to predict brain injury has been suggested because they are indicative of the inertial response of the brain. The objective of this study is to characterize the rotational kinematics of the head associated with concussive impacts using a large head acceleration dataset collected from human subjects. The helmets of 335 football players were instrumented with accelerometer arrays that measured head acceleration following head impacts sustained during play, resulting in data for 300,977 sub-concussive and 57 concussive head impacts. The average sub-concussive impact had a rotational acceleration of 1230 rad/s(2) and a rotational velocity of 5.5 rad/s, while the average concussive impact had a rotational acceleration of 5022 rad/s(2) and a rotational velocity of 22.3 rad/s. An injury risk curve was developed and a nominal injury value of 6383 rad/s(2) associated with 28.3 rad/s represents 50% risk of concussion. These data provide an increased understanding of the biomechanics associated with concussion and they provide critical insight into injury mechanisms, human tolerance to mechanical stimuli, and injury prevention techniques.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Guskiewicz, Kevin M; Mihalik, Jason P
Biomechanics of sport concussion: quest for the elusive injury threshold Journal Article
In: Exercise & Sport Sciences Reviews, vol. 39, pp. 4–11, 2011.
Abstract | BibTeX | Tags: Biomechanics
@article{Guskiewicz2011a,
title = {Biomechanics of sport concussion: quest for the elusive injury threshold},
author = {Guskiewicz, Kevin M and Mihalik, Jason P},
year = {2011},
date = {2011-01-01},
journal = {Exercise \& Sport Sciences Reviews},
volume = {39},
pages = {4--11},
address = {Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, and Curriculum in Human Movement Science, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599, USA. gus@email.unc.edu},
abstract = {Previous concussion biomechanics research has relied heavily on the animal model or laboratory reconstruction of concussive injuries captured on video footage. Real-time data collection involves a novel approach to better understanding the medical issues related to sport concussion. Recent studies suggest that a concussive injury threshold is elusive and may, in fact, be irrelevant when predicting the clinical outcome.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Patton, D; McIntosh, A; Kleiven, S
Brain loading in concussive head impacts: implications for injury prevention Journal Article
In: British Journal of Sports Medicine, vol. 45, pp. 318, 2011.
Abstract | BibTeX | Tags: Biomechanics
@article{Patton2011,
title = {Brain loading in concussive head impacts: implications for injury prevention},
author = {Patton, D and McIntosh, A and Kleiven, S},
year = {2011},
date = {2011-01-01},
journal = {British Journal of Sports Medicine},
volume = {45},
pages = {318},
abstract = {Background Concussion is a prominent injury risk in sport, but the mechanisms that cause concussion are unclear. An important debate centres on the roles of angular and linear head acceleration in the mechanism of concussion. Resolving this debate is a prerequisite for developing injury prevention methods. Objective To estimate the brain loading patterns in a case series of concussive and no-injury head impacts. To assess the relative affects of linear and angular acceleration on brain loading and injury. Design Biomechanical analysis of head impacts using the validated KTH human head finite element model to analyse brain loading patterns in reconstructed head impacts. Setting Professional male unhelmeted contact football. Participants Biomechanical data from a previous case series study of 40 male football players (concussed and no-injury). Main outcome measurements Maximum principle strain, a predictor of injury, was measured in discrete brain locations. Results The highest maximum principle strains were recorded in both the white and grey matter of the cerebrum. Strains in all brain regions were similar across all three grades of concussion (Cantu Revised Concussion Grading Guidelines), but lower (33-47%) for no-injury cases. Concussion was most correlated with strains in the brainstem and thalamus. Angular, rather than linear, resultant accelerations correlated higher to strains in all regions of the brain. Angular accelerations in the coronal plane and linear accelerations directed inferiorly had the greatest correlation to concussion and loss of consciousness. For linear accelerations, those directed laterally and inferiorly were most correlated with strain. Angular accelerations in the coronal plane correlated highly with strains in the brainstem, thalamus, and midbrain. Angular accelerations in the transverse plane correlated highly with strains in the cerebrum and corpus callosum. Conclusion Brain loading differences were observed between concussion and no-injury cases. Angular acceleration may play a more important role in the mechanism of concussion than linear acceleration.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Almosnino, Sivan; Pelland, Lucie; Stevenson, Joan M
Retest reliability of force-time variables of neck muscles under isometric conditions Journal Article
In: Journal of Athletic Training, vol. 45, pp. 453–458, 2010.
Abstract | BibTeX | Tags: Biomechanics
@article{Almosnino2010,
title = {Retest reliability of force-time variables of neck muscles under isometric conditions},
author = {Almosnino, Sivan and Pelland, Lucie and Stevenson, Joan M},
year = {2010},
date = {2010-01-01},
journal = {Journal of Athletic Training},
volume = {45},
pages = {453--458},
address = {School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada.},
abstract = {CONTEXT: Proper conditioning of the neck muscles may play a role in reducing the risk of neck injury and, possibly, concussions in contact sports. However, the ability to reliably measure the force-time-based variables that might be relevant for this purpose has not been addressed. OBJECTIVE: To assess the between-days reliability of discrete force-time-based variables of neck muscles during maximal voluntary isometric contractions in 5 directions. DESIGN: Cohort study. SETTING: University research center. PATIENTS OR OTHER PARTICIPANTS: Twenty-six highly physically active men (age = 21.6 +/- 2.1 years},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Greenwald, Richard M; Gwin, Joseph T; Chu, Jeffrey J; Crisco, Joseph J
Head impact severity measures for evaluating mild traumatic brain injury risk exposure Journal Article
In: Neurosurgery, vol. 62, pp. 789–98; discussion 798, 2008.
Abstract | BibTeX | Tags: Biomechanics
@article{Greenwald2008,
title = {Head impact severity measures for evaluating mild traumatic brain injury risk exposure},
author = {Greenwald, Richard M and Gwin, Joseph T and Chu, Jeffrey J and Crisco, Joseph J},
year = {2008},
date = {2008-01-01},
journal = {Neurosurgery},
volume = {62},
pages = {789--98; discussion 798},
address = {Simbex, Lebanon, New Hampshire, USA.},
abstract = {OBJECTIVE: The aims of this study were to quantify the sensitivity of various biomechanical measures (linear acceleration, rotational acceleration, impact duration, and impact location) of head impact to the clinical diagnosis of concussion in United States football players and to develop a novel measure of head impact severity combining these measures into a single score that better predicts the incidence of concussion. METHODS: On-field head impact data were collected from 449 football players at 13 organizations (n = 289,916) using in-helmet systems of six single-axis accelerometers. Concussions were diagnosed by medical staff and later associated with impact data. Principal component analysis and a weighting coefficient based on impact location were used to transform correlated head impact measures into a new composite variable, weighted principal component score (wPCS). The predictive power of linear acceleration, rotational acceleration, head injury criterion, and wPCS was quantified using receiver operating characteristic curves. The null hypothesis, that a measure was no more predictive than guessing, was tested (alpha = 0.05). In addition, receiver operating characteristic curves for wPCS and classical measures were directly compared to test the hypothesis that wPCS was more predictive of concussion than were classic measures (alpha = 0.05). RESULTS: When all of the impacts were considered, every biomechanical measure evaluated was statistically more predictive of concussion than guessing (P \< 0.005). However, for the top 1 and 2% of impacts based on linear acceleration, a subset that consisted of 82% of all diagnosed concussions, only wPCS was significantly more predictive of concussion than guessing (P \< 0.03); when compared with each other, wPCS was more predictive of concussion than were classical measures for the top 1 and 2% of all of the data (P \< 0.04). CONCLUSION: A weighted combination of several biomechanical inputs, including impact location, is more predictive of concussion than a single biomechanical measure. This study is the first to the authors' knowledge to quantify improvements in the sensitivity of a biomechanical measure to incidence of concussion when impact location is considered.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Beckwith, Jonathan G; Chu, Jeffrey J; Greenwald, Richard M
Validation of a noninvasive system for measuring head acceleration for use during boxing competition Journal Article
In: Journal of Applied Biomechanics, vol. 23, pp. 238–244, 2007.
Abstract | BibTeX | Tags: Biomechanics
@article{Beckwith2007,
title = {Validation of a noninvasive system for measuring head acceleration for use during boxing competition},
author = {Beckwith, Jonathan G and Chu, Jeffrey J and Greenwald, Richard M},
year = {2007},
date = {2007-01-01},
journal = {Journal of Applied Biomechanics},
volume = {23},
pages = {238--244},
address = {Simbex, Lebanon, NH, USA.},
abstract = {Although the epidemiology and mechanics of concussion in sports have been investigated for many years, the biomechanical factors that contribute to mild traumatic brain injury remain unclear because of the difficulties in measuring impact events in the field. The purpose of this study was to validate an instrumented boxing headgear (IBH) that can be used to measure impact severity and location during play. The instrumented boxing headgear data were processed to determine linear and rotational acceleration at the head center of gravity, impact location, and impact severity metrics, such as the Head Injury Criterion (HIC) and Gadd Severity Index (GSI). The instrumented boxing headgear was fitted to a Hybrid III (HIII) head form and impacted with a weighted pendulum to characterize accuracy and repeatability. Fifty-six impacts over 3 speeds and 5 locations were used to simulate blows most commonly observed in boxing. A high correlation between the HIII and instrumented boxing headgear was established for peak linear and rotational acceleration (r2= 0.91), HIC (r2 = 0.88), and GSI (r2 = 0.89). Mean location error was 9.7 +/- 5.2 masculine. Based on this study, the IBH is a valid system for measuring head acceleration and impact location that can be integrated into training and competition.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Pearson, B C; Armitage, K R; Horner, C W M; Carpenter, R H S
Saccadometry: the possible application of latency distribution measurement for monitoring concussion Journal Article
In: British Journal of Sports Medicine, vol. 41, pp. 610–612, 2007.
Abstract | BibTeX | Tags: Biomechanics
@article{Pearson2007,
title = {Saccadometry: the possible application of latency distribution measurement for monitoring concussion},
author = {Pearson, B C and Armitage, K R and Horner, C W M and Carpenter, R H S},
year = {2007},
date = {2007-01-01},
journal = {British Journal of Sports Medicine},
volume = {41},
pages = {610--612},
address = {Department of Physiology, Development and Neuroscience, University of Cambridge, UK. bcp22@cam.ac.uk},
abstract = {Premature return to play after concussion may have debilitating or even fatal consequences. Computerised neuropsychological test batteries are widely used to monitor recovery, but none meet all specified criteria. One possible alternative is to measure saccadic reaction time or latency. Latency reflects the operation of cerebral decision mechanisms, and is strongly influenced by many agents that impair cortical function. A portable, micro-miniature device (saccadometer) was used to record the eye movements of amateur boxers before and after competitive bouts. Individual latency distributions were significantly affected after blows to the head, though the effects seemed to be reversible, with recovery over a few days. This quantitative, objective and easy to use technique should perhaps be deployed more widely to evaluate its potential in monitoring the effects of sports-related head injuries.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Zumsteg, Dominik; Wennberg, Richard; Gutling, Eva; Hess, Klaus
Whiplash and concussion: similar acute changes in middle-latency SEPs Journal Article
In: Canadian Journal of Neurological Sciences, vol. 33, pp. 379–386, 2006.
Abstract | BibTeX | Tags: Biomechanics
@article{Zumsteg2006,
title = {Whiplash and concussion: similar acute changes in middle-latency SEPs},
author = {Zumsteg, Dominik and Wennberg, Richard and Gutling, Eva and Hess, Klaus},
year = {2006},
date = {2006-01-01},
journal = {Canadian Journal of Neurological Sciences},
volume = {33},
pages = {379--386},
address = {Krembil Neuroscience Centre, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada.},
abstract = {OBJECTIVE: Middle-latency somatosensory evoked potentials (SEPs) following median nerve stimulation can provide a sensitive measure of cortical function. We sought to determine whether the mechanical forces of whiplash injury or concussion alter normal processing of middle-latency SEPs. METHODS: In a cross-sectional pilot study 20 subjects with whiplash were investigated (50% between 0.5-2 months and 50% between 6-41 months post injury) and compared to 83 healthy subjects using a standard middle-latency SEP procedure. In a subsequent prospective study subjects with either acute whiplash (n=13) or Grade 3 concussion (n=16) were investigated within 48 hours and again three months post injury. RESULTS: In the pilot study the middle-latency SEP component N60 was significantly increased in the ten subjects investigated within two months after whiplash. In contrast, the ten subjects examined more than six months after injury showed normal latencies. In the prospective study N60 latencies were increased after whiplash and concussion when tested within 48 hours of injury. At three months, latencies were improved though still significantly different from controls post whiplash and concussion. CONCLUSIONS: Both whiplash injury and concussion alter processing of the middle-latency SEP component N60 in the acute post traumatic period. The acute changes appear to normalize between three-six months post injury. The SEP similarities suggest that the overlapping clinical symptomatology post whiplash and concussion may reflect a similar underlying mechanism of rotational mild traumatic brain injury.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Mourouzis, C; Koumoura, F
Sports-related maxillofacial fractures: a retrospective study of 125 patients Journal Article
In: International Journal of Oral & Maxillofacial Surgery, vol. 34, pp. 635–638, 2005.
Abstract | BibTeX | Tags: Biomechanics
@article{Mourouzis2005,
title = {Sports-related maxillofacial fractures: a retrospective study of 125 patients},
author = {Mourouzis, C and Koumoura, F},
year = {2005},
date = {2005-01-01},
journal = {International Journal of Oral \& Maxillofacial Surgery},
volume = {34},
pages = {635--638},
address = {Department of Oral and Maxillofacial Surgery, General Hospital of Attica KAT, Athens, Greece. cmourouzis@ath.forthnet.gr},
abstract = {This study assessed the spectrum of maxillofacial fractures sustained during sports in Greece, discuss the aetiology in different sports and suggest protective measures. One hundred and twenty-five patients suffered facial fractures as a result of different sport activities. The factors evaluated were: type of sport involved, age, sex, mechanism of injury, site of fractures, associated non-maxillofacial injuries and mode of treatment. The ratio male to female was 9:1 and the highest incidence of sport-related facial fractures was found in the 21-30 year age group. Football was the most common sport-related to facial fractures and the main mechanism of injury was that of impact against another player's head. The most common were the mandibular fractures, followed by zygoma fractures. Furthermore, the angle of the mandible is the highest risk region for fracture. The majority of patients needed surgical treatment. Facial fractures during sports mainly affect the young and the majority of the patients are amateur athletes. Although these injuries are not usually severe, initial hospitalisation and surgical interventions may be required. Team sports are responsible for the majority of facial fractures.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Crisco, Joseph J; Chu, Jeffrey J; Greenwald, Richard M
An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers Journal Article
In: Journal of Biomechanical Engineering, vol. 126, pp. 849–854, 2004.
Abstract | BibTeX | Tags: Biomechanics
@article{Crisco2004,
title = {An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers},
author = {Crisco, Joseph J and Chu, Jeffrey J and Greenwald, Richard M},
year = {2004},
date = {2004-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {126},
pages = {849--854},
address = {Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA. joseph_crisco@brown.edu},
abstract = {Accelerations of the head are the likely cause of concussion injury, but identifying the specific etiology of concussion has been difficult due to the lack of a valid animal or computer model. Contact sports, in which concussions are a rising health care concern, offer a unique research laboratory environment. However, measuring head acceleration in the field has many challenges including the need for large population sampling because of the relatively low incidence of concussions. We report a novel approach for calculating linear acceleration that can be incorporated into a head-mounted system for on-field use during contact sports. The advantages of this approach include the use of single-axis linear accelerometers, which reduce costs, and a nonorthogonal arrangement of the accelerometers, which simplifies the design criteria for a head-mounted and helmet compatible system. The purpose of this study was to describe the algorithm and evaluate its accuracy for measuring linear acceleration magnitude and impact location using computer simulation and experimental tests with various accelerometer configurations. A 10% error in magnitude and a 10 deg error in impact location were achieved using as few as six single-axis accelerometers mounted on a hemispherical headform.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Webbe, Frank M; Barth, Jeffrey T
Short-term and long-term outcome of athletic closed head injuries Journal Article
In: Clinics in Sports Medicine, vol. 22, pp. 577–592, 2003.
Abstract | BibTeX | Tags: Biomechanics
@article{Webbe2003a,
title = {Short-term and long-term outcome of athletic closed head injuries},
author = {Webbe, Frank M and Barth, Jeffrey T},
year = {2003},
date = {2003-01-01},
journal = {Clinics in Sports Medicine},
volume = {22},
pages = {577--592},
address = {School of Psychology, Florida Institute of Technology, Melbourne, FL 32901, USA.},
abstract = {The continued development of the sport environment as a laboratory for clinical investigation of mild head injury has greatly advanced the use of neuropsychological assessment in evaluating brain-injured athletes, and tracking their symptoms and recovery in an objective manner. The use of neurocognitive baseline measures has become critical in determining whether a brain-injured athlete has recovered function sufficiently to return to play. The rapid growth of computerized and web-based neurocognitive assessment measures provides an efficient, valid technology to put such testing within the reach of most institutions and organizations that field sport teams. Moreover, the knowledge of the recovery curve following mild head injury in the sport environment can be generalized to the management of MTBI in general clinical environments where baseline measures are unlikely. What we know today is that sideline assessments of severity are not predictive of which athletes will show the most typical 5- to 10-day recovery period and which will report persistent PCS complaints and exhibit impaired neurocognitive performance for an extended time. The research on mechanisms of brain injury in MTBI suggests that unpredictable, diffuse white-matter damage may control much of the variability in functional impairments and recovery duration. [References: 82]},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Vaccaro, Alexander R; Klein, Gregg R; Ciccoti, Michael; Pfaff, William L; Moulton, Mark J R; Hilibrand, Alan J; Watkins, Bob
Return to play criteria for the athlete with cervical spine injuries resulting in stinger and transient quadriplegia/paresis Journal Article
In: Spine Journal, vol. 2, pp. 351–356, 2002.
Abstract | BibTeX | Tags: Biomechanics
@article{Vaccaro2002,
title = {Return to play criteria for the athlete with cervical spine injuries resulting in stinger and transient quadriplegia/paresis},
author = {Vaccaro, Alexander R and Klein, Gregg R and Ciccoti, Michael and Pfaff, William L and Moulton, Mark J R and Hilibrand, Alan J and Watkins, Bob},
year = {2002},
date = {2002-01-01},
journal = {Spine Journal},
volume = {2},
pages = {351--356},
address = {Department of Orthopaedic Surgery, Thomas Jefferson University and the Rothman Institute, 925 Chestnut Street, 5th Floor, Philadelphia, PA 19107, USA. vaccaro3@yahoo.com},
abstract = {BACKGROUND CONTEXT: Fortunately, catastrophic cervical spinal cord injuries are relatively uncommon during athletic participation. Stinger and transient quadriplegia/paresis are more frequent injuries that have a wide spectrum of clinical severity and disabilities. Although the diagnosis of these injuries may not be clinically difficult, the treatment and decision about when or if the athlete may return to play after such an injury is often unclear. PURPOSE: This article reviews the current literature to help determine reasonable guidelines for return-to-play criteria after cervical spine injuries in the athlete. METHODS: The contemporary English literature and experience-based guidelines for return to play after cervical spine injuries in the athlete were reviewed. RESULTS: Despite the frequency of cervical-related injuries among athletes participating in contact and collision sports, no consensus exists within the medical field as to a standard guideline approach for return to preinjury activity level. CONCLUSION: The issue of return to play for an athlete after a cervical spine injury is controversial. Tremendous extrinsic pressures may be exerted on the physician from noninvolved and involved parties. The decision to return an athlete to a particular sport should be based on the mechanism of injury, objective anatomical injury (as demonstrated by clinical examination and radiographic evaluation) and an athlete's recovery response. [References: 21]},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Ruan, J; Prasad, P
The effects of skull thickness variations on human head dynamic impact responses Journal Article
In: Stapp Car Crash Journal, vol. 45, pp. 395–414, 2001.
Abstract | BibTeX | Tags: Biomechanics
@article{Ruan2001,
title = {The effects of skull thickness variations on human head dynamic impact responses},
author = {Ruan, J and Prasad, P},
year = {2001},
date = {2001-01-01},
journal = {Stapp Car Crash Journal},
volume = {45},
pages = {395--414},
address = {Ford Motor Company.},
abstract = {Variations in human skull thickness affecting human head dynamic impact responses were studied by finite element modeling techniques, experimental measurements, and histology examinations. The aims of the study were to better understand the influences of skull thickness variations on human head dynamic impact responses and the injury mechanisms of human head during direct impact. The thicknesses of the frontal bone of seven human cadaver skulls were measured using ultrasonic technology. These measurements were compared with previous experimental data. Histology of the skull was recorded and examined. The measured data were analyzed and then served as a reference to vary the skull thickness of a previously published three-dimensional finite element human head model to create four models with different skull thickness. The skull thicknesses modeled are 4.6 mm, 5.98 mm, 7.68 mm, and 9.61 mm. These models were impacted by a cylinder with a mass of 5.23 kg and an initial velocity of 6.33 m/s. Model responses were compared between models in terms of intracranial pressures, head impact accelerations, brain shear stresses, and skull von Mises stresses. It has been shown that the thickness of the skull influenced the dynamic responses of the head during direct impact. As skull thickness increased, skull deformation decreased as the skull absorbed less impact energy. However, this relationship cannot be linearly interpolated to the other parameters such as head acceleration and intracranial pressure responses. Based on model responses to half-sine wave pulses, skull and brain iso-stress curves were constructed for the thicker and thinner skulls. Thresholds for skull fracture and reversible concussion were established for the population represented by these skulls.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Sturmi, J E; Smith, C; Lombardo, J A
Mild brain trauma in sports. Diagnosis and treatment guidelines Journal Article
In: Sports Medicine, vol. 25, pp. 351–358, 1998.
Abstract | BibTeX | Tags: Biomechanics
@article{Sturmi1998,
title = {Mild brain trauma in sports. Diagnosis and treatment guidelines},
author = {Sturmi, J E and Smith, C and Lombardo, J A},
year = {1998},
date = {1998-01-01},
journal = {Sports Medicine},
volume = {25},
pages = {351--358},
address = {Ohio State University Athletic Department, Ohio State University, Columbus, USA.},
abstract = {Much has been written about the evaluation and management of mild brain trauma in sports. No less than 10 different 'guidelines' have been proposed and published to aid the clinician in the diagnosis of the condition. Too often, these guidelines have creating confusion instead of promoting an understanding of the spectrum of brain injury. As the understanding of the basic science of mild brain injury evolves, so must the approach to the concussed athlete. This article presents an up-to-date and clinically useful approach to the management of the athlete with a mild brain injury. The definition of 'concussion' is discussed and clarified and pertinent epidemiological data which highlight the importance of management skills as applied to athletes in a wide variety of sports are also reviewed. There is really no such thing as a 'mild concussion' if one considers the rare but catastrophic outcome of the second impact syndrome. For this reason, we review and expand upon the mechanisms of injury and pathophysiology. The accurate diagnosis of mild brain injury requires considerable experience, a high index of suspicion, a careful history and a series of examinations of the athlete, and a working knowledge of the athlete's personality and the likelihood of minimising their symptoms. The value of orientation questions pertinent to the athlete is now well established. Any focal neurological deficit or the deterioration of an athlete's condition warrants immediate hospitalisation, brain imaging and neurosurgical consultation. More commonly, athletes present with a brief alteration of consciousness, headache and amnesia and require careful examination and observation before returning to competition. The astute clinician will always err on the side of conservative management. The complete resolution of all symptoms before a return to play is imperative. Computerised tomography is very sensitive in the imaging of mild brain injuries. Neuropsychological testing is also very sensitive in the evaluation of brain injuries in athletes, and may become more clinically useful in the future. [References: 53]},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Hardy, W N; Khalil, T B; King, A I
Literature-review of head-injury biomechanics Journal Article
In: International Journal of Impact Engineering, vol. 15, pp. 561–586, 1994, ISSN: 0734-743X.
Abstract | Links | BibTeX | Tags: Biomechanics
@article{Hardy1994,
title = {Literature-review of head-injury biomechanics},
author = {Hardy, W N and Khalil, T B and King, A I},
doi = {10.1016/0734-743x(94)80034-7},
issn = {0734-743X},
year = {1994},
date = {1994-01-01},
journal = {International Journal of Impact Engineering},
volume = {15},
pages = {561--586},
abstract = {The high incidence of head injuries resulting from transportation system crashes, sports, military activities, falls, assaults, etc. contributes to a preponderance of head injury biomechanics research. A wealth of publications result, addressing phenomenological and mechanistic issues associated with head response to mechanical impact. This literature survey provides an assessment of hypothesized brain injury mechanisms, brain injury criteria, mathematical models of head injury and available techniques for measuring head kinematics and brain tissue deformations associated with exposure to dynamic loads.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Saunders, F W; Cledgett, P
Intracranial blood velocity in head-injury - A transcranial ultrasound doppler study Journal Article
In: Surgical Neurology, vol. 29, pp. 401–409, 1988, ISSN: 0090-3019.
BibTeX | Tags: Biomechanics
@article{Saunders1988,
title = {Intracranial blood velocity in head-injury - A transcranial ultrasound doppler study},
author = {Saunders, F W and Cledgett, P},
issn = {0090-3019},
year = {1988},
date = {1988-01-01},
journal = {Surgical Neurology},
volume = {29},
pages = {401--409},
address = {SAUNDERS, FW, QUEENS UNIV,DIV NEUROSURG,NONINVAS CEREBROVASC LAB,KINGSTON K7L 3N6,ONTARIO,CANADA.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Parkinson, D
The biomechanics of concussion Journal Article
In: Clinical Neurosurgery, vol. 29, pp. 131–145, 1982.
BibTeX | Tags: Biomechanics
@article{Parkinson1982,
title = {The biomechanics of concussion},
author = {Parkinson, D},
year = {1982},
date = {1982-01-01},
journal = {Clinical Neurosurgery},
volume = {29},
pages = {131--145},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Mihalik, J P; Lynall, R C; Wasserman, E B; Guskiewicz, K M; Marshall, S W
Evaluating the "threshold Theory": Can Head Impact Indicators Help? Journal Article
In: Medicine & Science in Sports & Exercise, vol. 49, no. 2, pp. 247–253, 2017.
@article{Mihalik2017,
title = {Evaluating the "threshold Theory": Can Head Impact Indicators Help?},
author = {Mihalik, J P and Lynall, R C and Wasserman, E B and Guskiewicz, K M and Marshall, S W},
doi = {10.1249/MSS.0000000000001089},
year = {2017},
date = {2017-01-01},
journal = {Medicine \& Science in Sports \& Exercise},
volume = {49},
number = {2},
pages = {247--253},
abstract = {Purpose This study aimed to determine the clinical utility of biomechanical head impact indicators by measuring the sensitivity, specificity, positive predictive value (PV+), and negative predictive value (PV-) of multiple thresholds. Methods Head impact biomechanics (n = 283,348) from 185 football players in one Division I program were collected. A multidisciplinary clinical team independently made concussion diagnoses (n = 24). We dichotomized each impact using diagnosis (yes = 24},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gilchrist, I; Moglo, K; Storr, M; Pelland, L
Effects of head flexion posture on the multidirectional static force capacity of the neck Journal Article
In: Clinical Biomechanics, vol. 37, pp. 44–52, 2016.
@article{Gilchrist2016,
title = {Effects of head flexion posture on the multidirectional static force capacity of the neck},
author = {Gilchrist, I and Moglo, K and Storr, M and Pelland, L},
doi = {10.1016/j.clinbiomech.2016.05.016},
year = {2016},
date = {2016-01-01},
journal = {Clinical Biomechanics},
volume = {37},
pages = {44--52},
abstract = {Background Neck muscle force protects vertebral alignment and resists potentially injurious loading of osteoligamentous structures during head impacts. As the majority of neck muscles generate moments about all three planes of motion, it is not clear how the force capacity of the neck might be modulated by direction of force application and head posture. The aim of our study was to measure the multidirectional moment-generating capacity of the neck and to evaluate effects of 20° of head flexion, a common head position in contact sports, on the measured capacity. Methods We conducted a cross-sectional study, with 25 males, 20-30 years old, performing maximum voluntary contractions, with ballistic intent, along eight directions, set at 45° intervals in the horizontal plane of the head. Three-dimensional moments at C3 and T1 were calculated using equations of static equilibrium. The variable of interest was the impulse of force generated from 0-50 ms. Effects of direction of force application and head posture, neutral and 20° flexion, were evaluated by two-way analysis of variance and linear regression. Findings Impulse of force was lower along diagonal planes, at 45° from the mid-sagittal plane, compared to orthogonal planes (P \< 0.001). Compared to neutral posture, head flexion produced a 55.2% decrease in impulse capacity at C3 and 45.9% at T1. Interpretation The risk of injury with head impact would intrinsically be higher along diagonal planes and with a 20° head down position due to a lower moment generating capacity of the neck in the first 50 ms of force application. © 2015 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Herman, D C; Barth, J T
Drop-jump landing varies with baseline neurocognition: Implications for anterior cruciate ligament injury risk and prevention Journal Article
In: American Journal of Sports Medicine, vol. 44, no. 9, pp. 2347–2353, 2016.
@article{Herman2016,
title = {Drop-jump landing varies with baseline neurocognition: Implications for anterior cruciate ligament injury risk and prevention},
author = {Herman, D C and Barth, J T},
doi = {10.1177/0363546516657338},
year = {2016},
date = {2016-01-01},
journal = {American Journal of Sports Medicine},
volume = {44},
number = {9},
pages = {2347--2353},
abstract = {Background: Neurocognitive status may be a risk factor for anterior cruciate ligament (ACL) injury. Neurocognitive domains such as visual attention, processing speed/reaction time, and dual-tasking may influence ACL injury risk via alterations to neuromuscular performance during athletic tasks. However, the relationship between neurocognition and performance during athletic tasks is not yet established. Hypothesis: Athletes with low baseline neurocognitive scores will demonstrate poorer jump landing performance compared with athletes with high baseline neurocognitive score. Study Design: Controlled laboratory study. Methods: Neurocognitive performance was measured using the Concussion Resolution Index (CRI). Three-dimensional kinematic and kinetic data of the dominant limb were collected for 37 recreational athletes while performing an unanticipated jump-landing task. Healthy, nonconcussed subjects were screened using a computer-based neurocognitive test into a high performers (HP; n = 20; average CRI percentile, 78th) and a low performers (LP; n = 17; average CRI percentile, 41st) group. The task consisted of a forward jump onto a force plate with an immediate rebound to a second target that was assigned 250 milliseconds before landing on the force plate. Kinematic and kinetic data were obtained during the first jump landing. Results: The LP group demonstrated significantly altered neuromuscular performance during the landing phase while completing the jump-landing task, including significantly increased peak vertical ground-reaction force (mean ± SD of LP vs HP: 1.81 ± 0.53 vs 1.38 ± 0.37 body weight [BW]; P \<.01), peak anterior tibial shear force (0.91 ± 0.17 vs 0.72 ± 0.22 BW; P \<.01), knee abduction moment (0.47 ± 0.56 vs 0.03 ± 0.64 BW × body height; P =.03), and knee abduction angle (6.1° ± 4.7° vs 1.3° ± 5.6°; P =.03), as well as decreased trunk flexion angle (9.6° ± 9.6° vs 16.4° ± 11.2°; P \<.01). Conclusion: Healthy athletes with lower baseline neurocognitive performance generate knee kinematic and kinetic patterns that are linked to ACL injury. Clinical Relevance: Neurocognitive testing using the CRI may be useful for identification of athletes at elevated risk for future ACL injury. © American Orthopaedic Society for Sports Medicine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Muise, D P; MacKenzie, S J; Sutherland, T M
Frequency and magnitude of head accelerations in a Canadian interuniversity sport football team’s training camp and season Journal Article
In: International Journal of Athletic Therapy & Training, vol. 21, no. 5, pp. 36–41, 2016.
@article{Muise2016,
title = {Frequency and magnitude of head accelerations in a Canadian interuniversity sport football team’s training camp and season},
author = {Muise, D P and MacKenzie, S J and Sutherland, T M},
doi = {10.1123/ijatt.2016-0005},
year = {2016},
date = {2016-01-01},
journal = {International Journal of Athletic Therapy \& Training},
volume = {21},
number = {5},
pages = {36--41},
abstract = {The increased awareness of concussion in sport has led to an examination of head impacts and the associated biomechanics that occur during these sporting events. The high rate of concussions in football makes it particularly relevant.1 The purpose of this study was to examine how frequently, and to what magnitude, Canadian University football players get hit in training camp and how this compares to practices and games in regular season. An ANOVA with repeated measures indicated that, on average, players were hit significantly more in games (45.2 hits) than training camp sessions (17.7 hits) and practices (8.0 hits), while training camp was associated with significantly more hits than practices (p \<. 001, $eta$2 =.392). Multiple positional differences were found. In particular, significantly more hits were experienced by offensive linemen (36.7 hits) and defensive linemen (31.6 hits) compared with all other positions (p \<.001, $eta$2 =.247). Study outcomes determined players/positions most at risk for concussion due to head impacts, which is beneficial in forming concussion prevention and assessment strategies. © 2016 Human Kinetics \textendashIJATT.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
O'Sullivan, D; Fife, G P; Pieter, W; Lim, T; Shin, I
Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks Journal Article
In: Journal of Sport and Health Science, vol. 5, no. 2, pp. 226–230, 2016.
@article{OSullivan2016,
title = {Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks},
author = {O'Sullivan, D and Fife, G P and Pieter, W and Lim, T and Shin, I},
doi = {10.1016/j.jshs.2015.01.004},
year = {2016},
date = {2016-01-01},
journal = {Journal of Sport and Health Science},
volume = {5},
number = {2},
pages = {226--230},
abstract = {Objective: The purpose of this study was to compare the effects of various taekwondo kicks and age (school level) in absolute terms and relative body mass on the resultant linear acceleration (RLA) of an instrumented head form. Methods: Forty-eight male (middle school: 16; high school: 16; university: 16) taekwondo athletes were recruited for this study. Subjects performed 10 turning, 10 jump spinning hook, and 10 jump back kicks on a Hybrid II head mounted on a height-adjustable frame. Results: A 2-way (School × Kick) MANOVA was used to determine the differences in RLA between schools (age groups) by type of kick. There was no univariate School main effect for absolute RLA ($eta$2 = 0.06) and RLA relative to body mass ($eta$2 = 0.06). No univariate Kick main effects were found for absolute ($eta$2 = 0.06) and relative RLA ($eta$2 = 0.06). Conclusion: It is of concern that RLA did not significantly differ between school levels, implying that young taekwondo athletes generate similar forces to their adult counterparts, possibly exposing young athletes to an increased risk for head injuries. © 2016.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cobb, B R; Zadnik, A M; Rowson, S
Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 50–60, 2016.
@article{Cobb2016,
title = {Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms},
author = {Cobb, B R and Zadnik, A M and Rowson, S},
doi = {10.1177/1754337115599133},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology},
volume = {230},
number = {1},
pages = {50--60},
abstract = {As advanced helmet testing methodologies are developed, the effect headform selection may have on the biomechanical impact response must be considered. This study sought to assess response differences between two of the most commonly used headforms, the Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms, through a series of helmeted impact tests. A total of 180 pendulum impact tests were conducted with three impactor velocities and six impact locations. Test condition-specific significant differences were found between the two headforms for peak linear and angular accelerations ($alpha$ = 0.05), although differences tended to be small. On average, the National Operating Committee on Standards for Athletic Equipment headform experienced higher peak linear (3.7 ± 7.8%) and angular (12.0 ± 21.6%) accelerations, with some of the largest differences associated with impacts to the facemask. Without the facemask impacts, the average differences in linear (1.8 ± 6.0%) and angular (9.6 ± 15.9%) acceleration would be lower. No significant differences were found in coefficient of variation values for linear (Hybrid III: 2.6 ± 2.3%, National Operating Committee on Standards for Athletic Equipment: 2.0 ± 1.4%) or angular (Hybrid III: 4.9 ± 4.0%; National Operating Committee on Standards for Athletic Equipment: 5.2 ± 5.8%) acceleration. These data have application toward development and validation of future helmet evaluation protocols and standards. © IMechE 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Patton, D A; McIntosh, A S
Considerations for the performance requirements and technical specifications of soft-shell padded headgear Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 29–42, 2016.
@article{Patton2016b,
title = {Considerations for the performance requirements and technical specifications of soft-shell padded headgear},
author = {Patton, D A and McIntosh, A S},
doi = {10.1177/1754337115615482},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology},
volume = {230},
number = {1},
pages = {29--42},
abstract = {Laboratory and epidemiological research in Australian football, rugby league and rugby union has demonstrated that commercially available soft-shell padded headgear is currently ineffective in reducing the risk of concussion. However, modified headgear studies have demonstrated that significant improvements in impact energy attenuation performance are possible with small design changes, such as increases in foam density and thickness. A literature review of the design, performance and use of headgear in Australian football, rugby league and rugby union was conducted. A total of 23 articles were identified using primary and secondary search strategies, which included epidemiological field studies, laboratory impact test studies and studies investigating the behaviours and attitudes of players. The results of the review were synthesised and used to identify injury reduction objectives and appropriate design criteria. The need for a headgear standard was identified and performance requirements were discussed, which drew upon human tolerance and sports-specific head impact exposure data. Usability and behavioural issues, which require consideration during the design process, were also assessed. © IMechE 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Caccese, J B; Buckley, T A; Kaminski, T W
Sway area and velocity correlated with MobileMat Balance Error Scoring System (BESS) scores Journal Article
In: Journal of Applied Biomechanics, vol. 32, no. 4, pp. 329–334, 2016.
@article{Caccese2016,
title = {Sway area and velocity correlated with MobileMat Balance Error Scoring System (BESS) scores},
author = {Caccese, J B and Buckley, T A and Kaminski, T W},
doi = {10.1123/jab.2015-0273},
year = {2016},
date = {2016-01-01},
journal = {Journal of Applied Biomechanics},
volume = {32},
number = {4},
pages = {329--334},
abstract = {The Balance Error Scoring System (BESS) is often used for sport-related concussion balance assessment. However, moderate intratester and intertester reliability may cause low initial sensitivity, suggesting that a more objective balance assessment method is needed. The MobileMat BESS was designed for objective BESS scoring, but the outcome measures must be validated with reliable balance measures. Thus, the purpose of this investigation was to compare MobileMat BESS scores to linear and nonlinear measures of balance. Eighty-eight healthy collegiate student-athletes (age: 20.0 ± 1.4 y, height: 177.7 ± 10.7 cm, mass: 74.8 ± 13.7 kg) completed the MobileMat BESS. MobileMat BESS scores were compared with 95% area, sway velocity, approximate entropy, and sample entropy. MobileMat BESS scores were significantly correlated with 95% area for single-leg (r =.332) and tandem firm (r =.474), and double-leg foam (r =.660); and with sway velocity for single-leg (r =.406) and tandem firm (r =.601), and double-leg (r =.575) and single-leg foam (r =.434). MobileMat BESS scores were not correlated with approximate or sample entropy. MobileMat BESS scores were low to moderately correlated with linear measures, suggesting the ability to identify changes in the center of mass-center of pressure relationship, but not higher-order processing associated with nonlinear measures. These results suggest that the MobileMat BESS may be a clinically-useful tool that provides objective linear balance measures. © 2016 Human Kinetics, Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
schmidtj uga edu Schmidt, Julianne D; Guskiewicz, Kevin M; Mihalik, Jason P; Blackburn, J Troy; Siegmund, Gunter P; Marshall, Stephen W
Head Impact Magnitude in American High School Football Journal Article
In: Pediatrics, vol. 138, no. 2, pp. 1–9, 2016, ISBN: 00314005.
@article{Schmidt2016,
title = {Head Impact Magnitude in American High School Football},
author = {schmidtj uga edu Schmidt, Julianne D and Guskiewicz, Kevin M and Mihalik, Jason P and Blackburn, J Troy and Siegmund, Gunter P and Marshall, Stephen W},
doi = {10.1542/peds.2015-4231},
isbn = {00314005},
year = {2016},
date = {2016-01-01},
journal = {Pediatrics},
volume = {138},
number = {2},
pages = {1--9},
abstract = {OBJECTIVES: To describe determinants of head impact magnitudes between various play aspects in high school football. METHODS: Thirty-two high school American football players wore Head Impact Telemetry System instrumented helmets to capture head impact magnitude (linear acceleration, rotational acceleration, and Head Impact Technology severity profile [HITsp]). We captured and analyzed video from 13 games (n = 3888 viewable head impacts) to determine the following play aspects: quarter, impact cause, play type, closing distance, double head impact, player's stance, player's action, direction of gaze, athletic readiness, level of anticipation, player stationary, ball possession, receiving ball, and snapping ball. We conducted random intercepts general linear mixed models to assess the differences in head impact magnitude between play aspects ($alpha$ = 0.05). RESULTS: The following aspects resulted in greater head impact magnitude: impacts during the second quarter (HITsp: P= .03); contact with another player (linear, rotational, HITsp: P \< .001); initial head impact when the head is struck twice (linear, rotational, HITsp: P \< .001); longer closing distances, especially when combined with a 3-point stance or when being struck in the head (linear: P = .03); the 2-point stance (linear, rotational, HITsp: P \< .001); and offensive linemen not snapping the ball compared with those snapping the ball (rotational: P = .02, HITsp: P = .02). CONCLUSIONS: Preventing head impacts caused by contact with another player may reduce head impact magnitude in high school football. Rule or coaching changes that reduce collisions after long closing distances, especially when combined with the 3-point stance or when a player is being struck in the head, should be considered. [ABSTRACT FROM AUTHOR]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Herman, Daniel C; Zaremski, Jason L; Vincent, Heather K; Vincent, Kevin R
Effect of neurocognition and concussion on musculoskeletal injury risk Journal Article
In: Current Sports Medicine Reports, vol. 14, pp. 194–199, 2015, ISSN: 1537-890X.
@article{Herman2015,
title = {Effect of neurocognition and concussion on musculoskeletal injury risk},
author = {Herman, Daniel C and Zaremski, Jason L and Vincent, Heather K and Vincent, Kevin R},
doi = {10.1249/JSR.0000000000000157},
issn = {1537-890X},
year = {2015},
date = {2015-01-01},
journal = {Current Sports Medicine Reports},
volume = {14},
pages = {194--199},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ji, S; Zhao, W
A Pre-computed Brain Response Atlas for Instantaneous Strain Estimation in Contact Sports Journal Article
In: Annals of Biomedical Engineering, vol. 43, pp. 1877–1895, 2015.
@article{Ji2015,
title = {A Pre-computed Brain Response Atlas for Instantaneous Strain Estimation in Contact Sports},
author = {Ji, S and Zhao, W},
year = {2015},
date = {2015-01-01},
journal = {Annals of Biomedical Engineering},
volume = {43},
pages = {1877--1895},
address = {Ji,Songbai. Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA, Songbai.Ji@Dartmouth.edu.},
abstract = {Finite element models of the human head play an important role in investigating the mechanisms of traumatic brain injury, including sports concussion. A critical limitation, however, is that they incur a substantial computational cost to simulate even a single impact. Therefore, current simulation schemes significantly hamper brain injury studies based on model-estimated tissue-level responses. In this study, we present a pre-computed brain response atlas (pcBRA) to substantially increase the simulation efficiency in estimating brain strains using isolated rotational acceleration impulses parameterized with four independent variables (peak magnitude and duration, and rotational axis azimuth and elevation angles) with values determined from on-field measurements. Using randomly generated testing datasets, the partially established pcBRA achieved a 100% success rate in interpolation based on element-wise differences in accumulated peak strain ([Formula: see text]) according to a "double-10%" criterion or average regional [Formula: see text] in generic regions and the corpus callosum. A similar performance was maintained in extrapolation. The pcBRA performance was further successfully validated against directly simulated responses from two independently measured typical real-world rotational profiles. The computational cost to estimate element-wise whole-brain or regional [Formula: see text] was 6 s and \<0.01 s, respectively, vs. $sim$50 min directly simulating a 40 ms impulse. These findings suggest the pcBRA could substantially increase the throughput in impact simulation without significant loss of accuracy from the estimation itself and, thus, its potential to accelerate the exploration of the mechanisms of sports concussion in general. If successful, the pcBRA may also become a diagnostic adjunct in conjunction with sensors that measure head impact kinematics on the field to objectively monitor and identify tissue-level brain trauma in real-time for "return-to-play" decision-making on the sideline.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Meier, T B; Bellgowan, P S; Singh, R; Kuplicki, R; Polanski, D W; Mayer, A R
Recovery of cerebral blood flow following sports-related concussion Journal Article
In: JAMA Neurology, vol. 72, pp. 530–538, 2015.
@article{Meier2015,
title = {Recovery of cerebral blood flow following sports-related concussion},
author = {Meier, T B and Bellgowan, P S and Singh, R and Kuplicki, R and Polanski, D W and Mayer, A R},
year = {2015},
date = {2015-01-01},
journal = {JAMA Neurology},
volume = {72},
pages = {530--538},
address = {Meier,Timothy B. The Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico2Laureate Institute for Brain Research, Tulsa, Oklahoma. Bellgowan,Patrick S F. Laureate Institute for Brain Research, Tulsa, Oklah},
abstract = {IMPORTANCE: Animal models suggest that reduced cerebral blood flow (CBF) is one of the most enduring physiological deficits following concussion. Despite this, longitudinal studies documenting serial changes in regional CBF following human concussion have yet to be performed. OBJECTIVE: To longitudinally assess the recovery of CBF in a carefully selected sample of collegiate athletes and compare time course of CBF recovery with that of cognitive and behavioral symptoms. DESIGN, SETTING, AND PARTICIPANTS: A cohort of collegiate football athletes (N = 44) participated in this mixed longitudinal and cross-sectional study at a private research institute specializing in neuroimaging between March 2012 and December 2013. Serial imaging occurred approximately 1 day, 1 week, and 1 month postconcussion for a subset of participants (n = 17). All athletes reported no premorbid mood disorders, anxiety disorders, substance abuse, or alcohol abuse. MAIN OUTCOMES AND MEASURES: Arterial spin labeling magnetic resonance imaging was used to collect voxelwise relative CBF at each visit. Neuropsychiatric evaluations and a brief cognitive screen were also performed at all 3 points. Clinicians trained in sports medicine provided an independent measure of real-world concussion outcome (ie, number of days withheld from competition). RESULTS: The results indicated both cognitive (simple reaction time) and neuropsychiatric symptoms at 1 day postinjury that resolved at either 1 week (cognitive; P \<.005) or 1 month (neuropsychiatric; P \<.005) postinjury. Imaging data suggested both cross-sectional (ie, healthy vs concussed athletes; P \<.05) and longitudinal (1 day and 1 week vs 1 month postinjury; P \<.001) evidence of CBF recovery in the right insular and superior temporal cortex. Importantly, CBF in the dorsal midinsular cortex was both decreased at 1 month postconcussion in slower-to-recover athletes (t11 = 3.45; P =.005) and was inversely related to the magnitude of initial psychiatric symptoms (Hamilton Depression Scale: r = -0.64},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tong, D C; Winter, T J; Jin, J; Bennett, A C; Waddell, J N
Quantification of subconcussive impact forces to the head using a forensic model Journal Article
In: Journal of Clinical Neuroscience, vol. 22, pp. 747–751, 2015.
@article{Tong2015,
title = {Quantification of subconcussive impact forces to the head using a forensic model},
author = {Tong, D C and Winter, T J and Jin, J and Bennett, A C and Waddell, J N},
year = {2015},
date = {2015-01-01},
journal = {Journal of Clinical Neuroscience},
volume = {22},
pages = {747--751},
address = {Tong,D C. Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin 9010, New Zealand. Electronic address: darryl.tong@otago.ac.nz. Winter,T J. Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dun},
abstract = {Concussive and subconcussive head injury is a global phenomenon that affects millions of people each year. Concussive injury has been extensively studied in sport, which has led to a greater understanding of the biomechanical forces involved and guidelines aimed at preventing athletes from playing while concussed. Subconcussive forces by definition do not meet the threshold for concussion but nonetheless may have significant long term consequences due to the repetitive pattern of injury to the head. Quantifying these impact forces using a forensic head model provides the groundwork for future studies by establishing a range or threshold of subconcussive impact forces that could be correlated with clinical assessments. The use of a forensic head model has distinct advantages in terms of ethics and safety.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Post, A; Blaine Hoshizaki, T
Rotational acceleration, brain tissue strain, and the relationship to concussion Journal Article
In: Journal of Biomechanical Engineering, vol. 137, pp. 1, 2015.
@article{Post2015c,
title = {Rotational acceleration, brain tissue strain, and the relationship to concussion},
author = {Post, A and {Blaine Hoshizaki}, T},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {137},
pages = {1},
abstract = {The mechanisms of concussion have been investigated by many researchers using a variety of methods. However, there remains much debate over the relationships between head kinematics from an impact and concussion. This review presents the links between research conducted in different disciplines to better understand the relationship between linear and rotational acceleration and brain strains that have been postulated as the root cause of concussion. These concepts are important when assigning performance variables for helmet development, car design, and protective innovation research.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Iraji, A; Benson, R R; Welch, R D; O'Neil, B J; Woodard, J L; Ayaz, S I; Kulek, A; Mika, V; Medado, P; Soltanian-Zadeh, H; Liu, T; Haacke, E M; Kou, Z
Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 1031–1045, 2015.
@article{Iraji2015,
title = {Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses},
author = {Iraji, A and Benson, R R and Welch, R D and O'Neil, B J and Woodard, J L and Ayaz, S I and Kulek, A and Mika, V and Medado, P and Soltanian-Zadeh, H and Liu, T and Haacke, E M and Kou, Z},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {1031--1045},
address = {Iraji,Armin. 1 Department of Biomedical Engineering, Wayne State University , Detroit, Michigan. Benson,Randall R. 2 Center for Neurologic Studies , Novi, Michigan. Welch,Robert D. 3 Department of Emergency Medicine, Wayne State University , Detroit, Mich},
abstract = {Mild traumatic brain injury (mTBI) accounts for more than 1 million emergency visits each year. Most of the injured stay in the emergency department for a few hours and are discharged home without a specific follow-up plan because of their negative clinical structural imaging. Advanced magnetic resonance imaging (MRI), particularly functional MRI (fMRI), has been reported as being sensitive to functional disturbances after brain injury. In this study, a cohort of 12 patients with mTBI were prospectively recruited from the emergency department of our local Level-1 trauma center for an advanced MRI scan at the acute stage. Sixteen age- and sex-matched controls were also recruited for comparison. Both group-based and individual-based independent component analysis of resting-state fMRI (rsfMRI) demonstrated reduced functional connectivity in both posterior cingulate cortex (PCC) and precuneus regions in comparison with controls, which is part of the default mode network (DMN). Further seed-based analysis confirmed reduced functional connectivity in these two regions and also demonstrated increased connectivity between these regions and other regions of the brain in mTBI. Seed-based analysis using the thalamus, hippocampus, and amygdala regions further demonstrated increased functional connectivity between these regions and other regions of the brain, particularly in the frontal lobe, in mTBI. Our data demonstrate alterations of multiple brain networks at the resting state, particularly increased functional connectivity in the frontal lobe, in response to brain concussion at the acute stage. Resting-state functional connectivity of the DMN could serve as a potential biomarker for improved detection of mTBI in the acute setting.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kerr, Z Y; Littleton, A C; Cox, L M; DeFreese, J D; Varangis, E; Lynall, R C; Schmidt, J D; Marshall, S W; Guskiewicz, K M
Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 1083–1089, 2015.
@article{Kerr2015ab,
title = {Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate},
author = {Kerr, Z Y and Littleton, A C and Cox, L M and DeFreese, J D and Varangis, E and Lynall, R C and Schmidt, J D and Marshall, S W and Guskiewicz, K M},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {1083--1089},
address = {Kerr,Zachary Y. 1 The Datalys Center for Sports Injury Research and Prevention, Indianapolis Indiana. Kerr,Zachary Y. 2 Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, University of North Carolina , Chapel Hill, North Carolina. Kerr,},
abstract = {Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information related to primary position played and participation in games and practice contacts during the pre-season, regular season, and post-season of each year of their high school, college, and professional football careers. Spring football for college was also included. We calculated contact exposure estimates for 64 former football players (n=32 college football only},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rousseau, P; Hoshizaki, T B
Defining the effective impact mass of elbow and shoulder strikes in ice hockey Journal Article
In: Sports Biomechanics, vol. 14, pp. 57–67, 2015.
@article{Rousseau2015,
title = {Defining the effective impact mass of elbow and shoulder strikes in ice hockey},
author = {Rousseau, P and Hoshizaki, T B},
year = {2015},
date = {2015-01-01},
journal = {Sports Biomechanics},
volume = {14},
pages = {57--67},
address = {Rousseau,Philippe. a Neurotrauma Impact Science Laboratory, Faculty of Health Sciences , University of Ottawa , Ottawa , ON , Canada.},
abstract = {Reconstruction of real-life events can be used to investigate the relationship between the mechanical parameters of the impact and concussion risk. Striking mass has typically been approximated as being the mass of the body part coming into contact with the head without accounting for the force applied by the striking athlete. Thus, the purpose of this study was to measure the effective impact mass of three common striking techniques in ice hockey. Fifteen participants were instructed to strike a suspended 50th percentile Hybrid III headform at least three times with their elbow or shoulder. Effective impact mass was calculated by measuring the change in velocity of the player and the headform. Mean effective impact mass for the extended elbow, tucked-in elbow, and shoulder check conditions were 4.8, 3.0, and 12.9 kg, respectively. Peak linear accelerations were lower than the values associated with concussion in American football which could be a reflection of the methodology used in this study as well as inherent differences between both sports.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Crisco, J J; Costa, L; Rich, R; Schwartz, J B; Wilcox, B
Surrogate headform accelerations associated with stick checks in girls' lacrosse Journal Article
In: Journal of Applied Biomechanics, vol. 31, pp. 122–127, 2015.
@article{Crisco2015,
title = {Surrogate headform accelerations associated with stick checks in girls' lacrosse},
author = {Crisco, J J and Costa, L and Rich, R and Schwartz, J B and Wilcox, B},
year = {2015},
date = {2015-01-01},
journal = {Journal of Applied Biomechanics},
volume = {31},
pages = {122--127},
address = {Crisco,Joseph J. Bioengineering Laboratory, Department of Orthopaedics, Warren Alpert Medical School of Brown University, and Rhode Island Hospital, Providence, RI.},
abstract = {Girls' lacrosse is fundamentally a different sport than boys' lacrosse, and girls are not required to wear protective headgear. Recent epidemiological studies have found that stick checks are the leading cause of concussion injury in girls' lacrosse. The purpose of this study was to determine stick check speeds and estimate the head acceleration associated with direct checks to the head. In addition, we briefly examine if commercially available headgear can mitigate the accelerations. Seven (n = 7) experienced female lacrosse players checked, with varying severity, a NOSCAE and an ASTM headform. Stick speed at impact and the associated peak linear accelerations of the headform were recorded. The NOCSAE headform was fitted with four commercially available headgear and similar stick impact testing was performed. The median stick impact speed was 8.1 m/s and 777 deg/s. At these speeds, peak linear acceleration was approximately 60g. Three out of the four headgear significantly reduced the peak linear acceleration when compared with the bare headform. These data serve as baseline for understanding the potential mechanism and reduction of concussions from stick impacts in girls' lacrosse.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Oeur, R A; Karton, C; Post, A; Rousseau, P; Hoshizaki, T B; Marshall, S; Brien, S E; Smith, A; Cusimano, M D; Gilchrist, M D
In: Journal of Neurosurgery, vol. 123, no. 2, pp. 415–422, 2015.
@article{Oeur2015,
title = {A comparison of head dynamic response and brain tissue stress and strain using accident reconstructions for concussion, concussion with persistent postconcussive symptoms, and subdural hematoma},
author = {Oeur, R A and Karton, C and Post, A and Rousseau, P and Hoshizaki, T B and Marshall, S and Brien, S E and Smith, A and Cusimano, M D and Gilchrist, M D},
doi = {10.3171/2014.10.JNS14440},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurosurgery},
volume = {123},
number = {2},
pages = {415--422},
abstract = {Object Concussions typically resolve within several days, but in a few cases the symptoms last for a month or longer and are termed persistent postconcussive symptoms (PPCS). These persisting symptoms may also be associated with more serious brain trauma similar to subdural hematoma (SDH). The objective of this study was to investigate the head dynamic and brain tissue responses of injury reconstructions resulting in concussion, PPCS, and SDH. Methods Reconstruction cases were obtained from sports medicine clinics and hospitals. All subjects received a direct blow to the head resulting in symptoms. Those symptoms that resolved in 9 days or fewer were defined as concussions (n = 3). Those with symptoms lasting longer than 18 months were defined as PPCS (n = 3), and 3 patients presented with SDHs (n = 3). A Hybrid III headform was used in reconstruction to obtain linear and rotational accelerations of the head. These dynamic response data were then input into the University College Dublin Brain Trauma Model to calculate maximum principal strain and von Mises stress. A Kruskal-Wallis test followed by Tukey post hoc tests were used to compare head dynamic and brain tissue responses between injury groups. Statistical significance was set at p \< 0.05. Results A significant difference was identified for peak resultant linear and rotational acceleration between injury groups. Post hoc analyses revealed the SDH group had higher linear and rotational acceleration responses (316 g and 23,181 rad/sec2, respectively) than the concussion group (149 g and 8111 rad/sec2, respectively; p \< 0.05). No significant differences were found between groups for either brain tissue measures of maximum principal strain or von Mises stress. Conclusions The reconstruction of accidents resulting in a concussion with transient symptoms (low severity) and SDHs revealed a positive relationship between an increase in head dynamic response and the risk for more serious brain injury. This type of relationship was not found for brain tissue stress and strain results derived by finite element analysis. Future research should be undertaken using a larger sample size to confirm these initial findings. Understanding the relationship between the head dynamic and brain tissue response and the nature of the injury provides important information for developing strategies for injury prevention. © AANS, 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Post, A; Kendall, M; Koncan, D; Cournoyer, J; Blaine Hoshizaki, T; Gilchrist, M D; Brien, S; Cusimano, M D; Marshall, S
Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling Journal Article
In: Journal of the Mechanical Behavior of Biomedical Materials, vol. 41, pp. 325–335, 2015.
@article{Post2015,
title = {Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling},
author = {Post, A and Kendall, M and Koncan, D and Cournoyer, J and {Blaine Hoshizaki}, T and Gilchrist, M D and Brien, S and Cusimano, M D and Marshall, S},
year = {2015},
date = {2015-01-01},
journal = {Journal of the Mechanical Behavior of Biomedical Materials},
volume = {41},
pages = {325--335},
address = {Post,Andrew. Human Kinetics, University of Ottawa, Ottawa, ON, Canada K1N 6N5. Electronic address: apost@uottawa.ca. Kendall,Marshall. Human Kinetics, University of Ottawa, Ottawa, ON, Canada K1N 6N5. Koncan,David. Human Kinetics, University of Ottawa, Ot},
abstract = {Concussions occur 1.7 million times a year in North America, and account for approximately 75% of all traumatic brain injuries (TBI). Concussions usually cause transient symptoms but 10 to 20% of patients can have symptoms that persist longer than a month. The purpose of this research was to use reconstructions and finite element modeling to determine the brain tissue stresses and strains that occur in impacts that led to persistent post concussive symptoms (PCS) in hospitalized patients. A total of 21 PCS patients had their head impacts reconstructed using computational, physical and finite element methods. The dependent variables measured were maximum principal strain, von Mises stress (VMS), strain rate, and product of strain and strain rate. For maximum principal strain alone there were large regions of brain tissue incurring 30 to 40% strain. This large field of strain was also evident when using strain rate, product of strain and strain rate. In addition, VMS also showed large magnitudes of stress throughout the cerebrum tissues. The distribution of strains throughout the brain tissues indicated peak responses were always present in the grey matter (0.481), with the white matter showing significantly lower strains (0.380) (p\<0.05). The impact conditions of the PCS cases were severe in nature, with impacts against non-compliant surfaces (concrete, steel, ice) resulting in higher brain deformation. PCS biomechanical parameters were shown to fit between those that have been shown to cause transient post concussive symptoms and those that lead to actual pathologic damage like contusion, however, values of all metrics were characterized by large variance and high average responses. This data supports the theory that there exists a progressive continuum of impacts that lead to a progressive continuum of related severity of injury from transient symptoms to pathological damage.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mihalik, J P; Lynall, R C; Wasserman, E B; Guskiewicz, K M; Marshall, S W
Evaluating the "threshold Theory": Can Head Impact Indicators Help? Journal Article
In: Medicine & Science in Sports & Exercise, vol. 49, no. 2, pp. 247–253, 2017.
Abstract | Links | BibTeX | Tags: Biomechanics, Brain Injury, Concussion, sport injury
@article{Mihalik2017,
title = {Evaluating the "threshold Theory": Can Head Impact Indicators Help?},
author = {Mihalik, J P and Lynall, R C and Wasserman, E B and Guskiewicz, K M and Marshall, S W},
doi = {10.1249/MSS.0000000000001089},
year = {2017},
date = {2017-01-01},
journal = {Medicine \& Science in Sports \& Exercise},
volume = {49},
number = {2},
pages = {247--253},
abstract = {Purpose This study aimed to determine the clinical utility of biomechanical head impact indicators by measuring the sensitivity, specificity, positive predictive value (PV+), and negative predictive value (PV-) of multiple thresholds. Methods Head impact biomechanics (n = 283,348) from 185 football players in one Division I program were collected. A multidisciplinary clinical team independently made concussion diagnoses (n = 24). We dichotomized each impact using diagnosis (yes = 24},
keywords = {Biomechanics, Brain Injury, Concussion, sport injury},
pubstate = {published},
tppubtype = {article}
}
Cobb, B R; Zadnik, A M; Rowson, S
Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 50–60, 2016.
Abstract | Links | BibTeX | Tags: Acceleration, Accident prevention, Angular acceleration, Biomechanics, Brain Injury, Coefficient of variation values, Comparative analysis, Concussion, Equipment, Evaluation protocol, helmet testing, Linear acceleration, Linear accelerations, Rotational acceleration, Safety devices, Sporting goods, standards
@article{Cobb2016,
title = {Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms},
author = {Cobb, B R and Zadnik, A M and Rowson, S},
doi = {10.1177/1754337115599133},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology},
volume = {230},
number = {1},
pages = {50--60},
abstract = {As advanced helmet testing methodologies are developed, the effect headform selection may have on the biomechanical impact response must be considered. This study sought to assess response differences between two of the most commonly used headforms, the Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms, through a series of helmeted impact tests. A total of 180 pendulum impact tests were conducted with three impactor velocities and six impact locations. Test condition-specific significant differences were found between the two headforms for peak linear and angular accelerations ($alpha$ = 0.05), although differences tended to be small. On average, the National Operating Committee on Standards for Athletic Equipment headform experienced higher peak linear (3.7 ± 7.8%) and angular (12.0 ± 21.6%) accelerations, with some of the largest differences associated with impacts to the facemask. Without the facemask impacts, the average differences in linear (1.8 ± 6.0%) and angular (9.6 ± 15.9%) acceleration would be lower. No significant differences were found in coefficient of variation values for linear (Hybrid III: 2.6 ± 2.3%, National Operating Committee on Standards for Athletic Equipment: 2.0 ± 1.4%) or angular (Hybrid III: 4.9 ± 4.0%; National Operating Committee on Standards for Athletic Equipment: 5.2 ± 5.8%) acceleration. These data have application toward development and validation of future helmet evaluation protocols and standards. © IMechE 2015.},
keywords = {Acceleration, Accident prevention, Angular acceleration, Biomechanics, Brain Injury, Coefficient of variation values, Comparative analysis, Concussion, Equipment, Evaluation protocol, helmet testing, Linear acceleration, Linear accelerations, Rotational acceleration, Safety devices, Sporting goods, standards},
pubstate = {published},
tppubtype = {article}
}
Gilchrist, I; Moglo, K; Storr, M; Pelland, L
Effects of head flexion posture on the multidirectional static force capacity of the neck Journal Article
In: Clinical Biomechanics, vol. 37, pp. 44–52, 2016.
Abstract | Links | BibTeX | Tags: adult, Article, Biomechanics, BIOPHYSICS, body equilibrium, body posture, Cervical spine, Concussions, contact sport, cross-sectional study, Dynamometry, force, head flexion, head movement, head position, human, human experiment, Male, Muscle, muscle contraction, muscle strength, neck injury, Neck muscle, neck strength, priority journal
@article{Gilchrist2016,
title = {Effects of head flexion posture on the multidirectional static force capacity of the neck},
author = {Gilchrist, I and Moglo, K and Storr, M and Pelland, L},
doi = {10.1016/j.clinbiomech.2016.05.016},
year = {2016},
date = {2016-01-01},
journal = {Clinical Biomechanics},
volume = {37},
pages = {44--52},
abstract = {Background Neck muscle force protects vertebral alignment and resists potentially injurious loading of osteoligamentous structures during head impacts. As the majority of neck muscles generate moments about all three planes of motion, it is not clear how the force capacity of the neck might be modulated by direction of force application and head posture. The aim of our study was to measure the multidirectional moment-generating capacity of the neck and to evaluate effects of 20° of head flexion, a common head position in contact sports, on the measured capacity. Methods We conducted a cross-sectional study, with 25 males, 20-30 years old, performing maximum voluntary contractions, with ballistic intent, along eight directions, set at 45° intervals in the horizontal plane of the head. Three-dimensional moments at C3 and T1 were calculated using equations of static equilibrium. The variable of interest was the impulse of force generated from 0-50 ms. Effects of direction of force application and head posture, neutral and 20° flexion, were evaluated by two-way analysis of variance and linear regression. Findings Impulse of force was lower along diagonal planes, at 45° from the mid-sagittal plane, compared to orthogonal planes (P \< 0.001). Compared to neutral posture, head flexion produced a 55.2% decrease in impulse capacity at C3 and 45.9% at T1. Interpretation The risk of injury with head impact would intrinsically be higher along diagonal planes and with a 20° head down position due to a lower moment generating capacity of the neck in the first 50 ms of force application. © 2015 Elsevier Ltd. All rights reserved.},
keywords = {adult, Article, Biomechanics, BIOPHYSICS, body equilibrium, body posture, Cervical spine, Concussions, contact sport, cross-sectional study, Dynamometry, force, head flexion, head movement, head position, human, human experiment, Male, Muscle, muscle contraction, muscle strength, neck injury, Neck muscle, neck strength, priority journal},
pubstate = {published},
tppubtype = {article}
}
Herman, D C; Barth, J T
Drop-jump landing varies with baseline neurocognition: Implications for anterior cruciate ligament injury risk and prevention Journal Article
In: American Journal of Sports Medicine, vol. 44, no. 9, pp. 2347–2353, 2016.
Abstract | Links | BibTeX | Tags: ACL, Biomechanics, Injury prevention, Motion analysis
@article{Herman2016,
title = {Drop-jump landing varies with baseline neurocognition: Implications for anterior cruciate ligament injury risk and prevention},
author = {Herman, D C and Barth, J T},
doi = {10.1177/0363546516657338},
year = {2016},
date = {2016-01-01},
journal = {American Journal of Sports Medicine},
volume = {44},
number = {9},
pages = {2347--2353},
abstract = {Background: Neurocognitive status may be a risk factor for anterior cruciate ligament (ACL) injury. Neurocognitive domains such as visual attention, processing speed/reaction time, and dual-tasking may influence ACL injury risk via alterations to neuromuscular performance during athletic tasks. However, the relationship between neurocognition and performance during athletic tasks is not yet established. Hypothesis: Athletes with low baseline neurocognitive scores will demonstrate poorer jump landing performance compared with athletes with high baseline neurocognitive score. Study Design: Controlled laboratory study. Methods: Neurocognitive performance was measured using the Concussion Resolution Index (CRI). Three-dimensional kinematic and kinetic data of the dominant limb were collected for 37 recreational athletes while performing an unanticipated jump-landing task. Healthy, nonconcussed subjects were screened using a computer-based neurocognitive test into a high performers (HP; n = 20; average CRI percentile, 78th) and a low performers (LP; n = 17; average CRI percentile, 41st) group. The task consisted of a forward jump onto a force plate with an immediate rebound to a second target that was assigned 250 milliseconds before landing on the force plate. Kinematic and kinetic data were obtained during the first jump landing. Results: The LP group demonstrated significantly altered neuromuscular performance during the landing phase while completing the jump-landing task, including significantly increased peak vertical ground-reaction force (mean ± SD of LP vs HP: 1.81 ± 0.53 vs 1.38 ± 0.37 body weight [BW]; P \<.01), peak anterior tibial shear force (0.91 ± 0.17 vs 0.72 ± 0.22 BW; P \<.01), knee abduction moment (0.47 ± 0.56 vs 0.03 ± 0.64 BW × body height; P =.03), and knee abduction angle (6.1° ± 4.7° vs 1.3° ± 5.6°; P =.03), as well as decreased trunk flexion angle (9.6° ± 9.6° vs 16.4° ± 11.2°; P \<.01). Conclusion: Healthy athletes with lower baseline neurocognitive performance generate knee kinematic and kinetic patterns that are linked to ACL injury. Clinical Relevance: Neurocognitive testing using the CRI may be useful for identification of athletes at elevated risk for future ACL injury. © American Orthopaedic Society for Sports Medicine.},
keywords = {ACL, Biomechanics, Injury prevention, Motion analysis},
pubstate = {published},
tppubtype = {article}
}
Muise, D P; MacKenzie, S J; Sutherland, T M
Frequency and magnitude of head accelerations in a Canadian interuniversity sport football team’s training camp and season Journal Article
In: International Journal of Athletic Therapy & Training, vol. 21, no. 5, pp. 36–41, 2016.
Abstract | Links | BibTeX | Tags: Biomechanics, Concussion, mTBI, Sport
@article{Muise2016,
title = {Frequency and magnitude of head accelerations in a Canadian interuniversity sport football team’s training camp and season},
author = {Muise, D P and MacKenzie, S J and Sutherland, T M},
doi = {10.1123/ijatt.2016-0005},
year = {2016},
date = {2016-01-01},
journal = {International Journal of Athletic Therapy \& Training},
volume = {21},
number = {5},
pages = {36--41},
abstract = {The increased awareness of concussion in sport has led to an examination of head impacts and the associated biomechanics that occur during these sporting events. The high rate of concussions in football makes it particularly relevant.1 The purpose of this study was to examine how frequently, and to what magnitude, Canadian University football players get hit in training camp and how this compares to practices and games in regular season. An ANOVA with repeated measures indicated that, on average, players were hit significantly more in games (45.2 hits) than training camp sessions (17.7 hits) and practices (8.0 hits), while training camp was associated with significantly more hits than practices (p \<. 001, $eta$2 =.392). Multiple positional differences were found. In particular, significantly more hits were experienced by offensive linemen (36.7 hits) and defensive linemen (31.6 hits) compared with all other positions (p \<.001, $eta$2 =.247). Study outcomes determined players/positions most at risk for concussion due to head impacts, which is beneficial in forming concussion prevention and assessment strategies. © 2016 Human Kinetics \textendashIJATT.},
keywords = {Biomechanics, Concussion, mTBI, Sport},
pubstate = {published},
tppubtype = {article}
}
O'Sullivan, D; Fife, G P; Pieter, W; Lim, T; Shin, I
Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks Journal Article
In: Journal of Sport and Health Science, vol. 5, no. 2, pp. 226–230, 2016.
Abstract | Links | BibTeX | Tags: accelerometer, Adolescent, age distribution, analytical parameters, Article, athlete, Biomechanics, body mass, Concussion, controlled study, head injury, high school student, human, injury, Male, Martial Arts, middle school student, priority journal, resultant linear acceleration, taekwondo, university student
@article{OSullivan2016,
title = {Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks},
author = {O'Sullivan, D and Fife, G P and Pieter, W and Lim, T and Shin, I},
doi = {10.1016/j.jshs.2015.01.004},
year = {2016},
date = {2016-01-01},
journal = {Journal of Sport and Health Science},
volume = {5},
number = {2},
pages = {226--230},
abstract = {Objective: The purpose of this study was to compare the effects of various taekwondo kicks and age (school level) in absolute terms and relative body mass on the resultant linear acceleration (RLA) of an instrumented head form. Methods: Forty-eight male (middle school: 16; high school: 16; university: 16) taekwondo athletes were recruited for this study. Subjects performed 10 turning, 10 jump spinning hook, and 10 jump back kicks on a Hybrid II head mounted on a height-adjustable frame. Results: A 2-way (School × Kick) MANOVA was used to determine the differences in RLA between schools (age groups) by type of kick. There was no univariate School main effect for absolute RLA ($eta$2 = 0.06) and RLA relative to body mass ($eta$2 = 0.06). No univariate Kick main effects were found for absolute ($eta$2 = 0.06) and relative RLA ($eta$2 = 0.06). Conclusion: It is of concern that RLA did not significantly differ between school levels, implying that young taekwondo athletes generate similar forces to their adult counterparts, possibly exposing young athletes to an increased risk for head injuries. © 2016.},
keywords = {accelerometer, Adolescent, age distribution, analytical parameters, Article, athlete, Biomechanics, body mass, Concussion, controlled study, head injury, high school student, human, injury, Male, Martial Arts, middle school student, priority journal, resultant linear acceleration, taekwondo, university student},
pubstate = {published},
tppubtype = {article}
}
Patton, D A; McIntosh, A S
Considerations for the performance requirements and technical specifications of soft-shell padded headgear Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 29–42, 2016.
Abstract | Links | BibTeX | Tags: Australian football, Biomechanics, Concussion, Design, Head Injuries, head injury, headgear, Injury prevention, protective equipment, rugby, Sports
@article{Patton2016b,
title = {Considerations for the performance requirements and technical specifications of soft-shell padded headgear},
author = {Patton, D A and McIntosh, A S},
doi = {10.1177/1754337115615482},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology},
volume = {230},
number = {1},
pages = {29--42},
abstract = {Laboratory and epidemiological research in Australian football, rugby league and rugby union has demonstrated that commercially available soft-shell padded headgear is currently ineffective in reducing the risk of concussion. However, modified headgear studies have demonstrated that significant improvements in impact energy attenuation performance are possible with small design changes, such as increases in foam density and thickness. A literature review of the design, performance and use of headgear in Australian football, rugby league and rugby union was conducted. A total of 23 articles were identified using primary and secondary search strategies, which included epidemiological field studies, laboratory impact test studies and studies investigating the behaviours and attitudes of players. The results of the review were synthesised and used to identify injury reduction objectives and appropriate design criteria. The need for a headgear standard was identified and performance requirements were discussed, which drew upon human tolerance and sports-specific head impact exposure data. Usability and behavioural issues, which require consideration during the design process, were also assessed. © IMechE 2015.},
keywords = {Australian football, Biomechanics, Concussion, Design, Head Injuries, head injury, headgear, Injury prevention, protective equipment, rugby, Sports},
pubstate = {published},
tppubtype = {article}
}
schmidtj uga edu Schmidt, Julianne D; Guskiewicz, Kevin M; Mihalik, Jason P; Blackburn, J Troy; Siegmund, Gunter P; Marshall, Stephen W
Head Impact Magnitude in American High School Football Journal Article
In: Pediatrics, vol. 138, no. 2, pp. 1–9, 2016, ISBN: 00314005.
Abstract | Links | BibTeX | Tags: ACCELERATION (Mechanics), Biomechanics, DATA analysis -- Software, Football injuries -- Prevention, Head injuries -- Prevention, HIGH school athletes, SAFETY hats, SAMPLING (Statistics), VIDEO recording
@article{Schmidt2016,
title = {Head Impact Magnitude in American High School Football},
author = {schmidtj uga edu Schmidt, Julianne D and Guskiewicz, Kevin M and Mihalik, Jason P and Blackburn, J Troy and Siegmund, Gunter P and Marshall, Stephen W},
doi = {10.1542/peds.2015-4231},
isbn = {00314005},
year = {2016},
date = {2016-01-01},
journal = {Pediatrics},
volume = {138},
number = {2},
pages = {1--9},
abstract = {OBJECTIVES: To describe determinants of head impact magnitudes between various play aspects in high school football. METHODS: Thirty-two high school American football players wore Head Impact Telemetry System instrumented helmets to capture head impact magnitude (linear acceleration, rotational acceleration, and Head Impact Technology severity profile [HITsp]). We captured and analyzed video from 13 games (n = 3888 viewable head impacts) to determine the following play aspects: quarter, impact cause, play type, closing distance, double head impact, player's stance, player's action, direction of gaze, athletic readiness, level of anticipation, player stationary, ball possession, receiving ball, and snapping ball. We conducted random intercepts general linear mixed models to assess the differences in head impact magnitude between play aspects ($alpha$ = 0.05). RESULTS: The following aspects resulted in greater head impact magnitude: impacts during the second quarter (HITsp: P= .03); contact with another player (linear, rotational, HITsp: P \< .001); initial head impact when the head is struck twice (linear, rotational, HITsp: P \< .001); longer closing distances, especially when combined with a 3-point stance or when being struck in the head (linear: P = .03); the 2-point stance (linear, rotational, HITsp: P \< .001); and offensive linemen not snapping the ball compared with those snapping the ball (rotational: P = .02, HITsp: P = .02). CONCLUSIONS: Preventing head impacts caused by contact with another player may reduce head impact magnitude in high school football. Rule or coaching changes that reduce collisions after long closing distances, especially when combined with the 3-point stance or when a player is being struck in the head, should be considered. [ABSTRACT FROM AUTHOR]},
keywords = {ACCELERATION (Mechanics), Biomechanics, DATA analysis -- Software, Football injuries -- Prevention, Head injuries -- Prevention, HIGH school athletes, SAFETY hats, SAMPLING (Statistics), VIDEO recording},
pubstate = {published},
tppubtype = {article}
}
Caccese, J B; Buckley, T A; Kaminski, T W
Sway area and velocity correlated with MobileMat Balance Error Scoring System (BESS) scores Journal Article
In: Journal of Applied Biomechanics, vol. 32, no. 4, pp. 329–334, 2016.
Abstract | Links | BibTeX | Tags: Approximate entropy, Balance, Balancing, Biomechanics, BIOPHYSICS, Concussion, Entropy, Linear measures, Nonlinear measure, ORTHOPEDICS, Outcome measures, postural stability, Sample entropy, Scoring systems
@article{Caccese2016,
title = {Sway area and velocity correlated with MobileMat Balance Error Scoring System (BESS) scores},
author = {Caccese, J B and Buckley, T A and Kaminski, T W},
doi = {10.1123/jab.2015-0273},
year = {2016},
date = {2016-01-01},
journal = {Journal of Applied Biomechanics},
volume = {32},
number = {4},
pages = {329--334},
abstract = {The Balance Error Scoring System (BESS) is often used for sport-related concussion balance assessment. However, moderate intratester and intertester reliability may cause low initial sensitivity, suggesting that a more objective balance assessment method is needed. The MobileMat BESS was designed for objective BESS scoring, but the outcome measures must be validated with reliable balance measures. Thus, the purpose of this investigation was to compare MobileMat BESS scores to linear and nonlinear measures of balance. Eighty-eight healthy collegiate student-athletes (age: 20.0 ± 1.4 y, height: 177.7 ± 10.7 cm, mass: 74.8 ± 13.7 kg) completed the MobileMat BESS. MobileMat BESS scores were compared with 95% area, sway velocity, approximate entropy, and sample entropy. MobileMat BESS scores were significantly correlated with 95% area for single-leg (r =.332) and tandem firm (r =.474), and double-leg foam (r =.660); and with sway velocity for single-leg (r =.406) and tandem firm (r =.601), and double-leg (r =.575) and single-leg foam (r =.434). MobileMat BESS scores were not correlated with approximate or sample entropy. MobileMat BESS scores were low to moderately correlated with linear measures, suggesting the ability to identify changes in the center of mass-center of pressure relationship, but not higher-order processing associated with nonlinear measures. These results suggest that the MobileMat BESS may be a clinically-useful tool that provides objective linear balance measures. © 2016 Human Kinetics, Inc.},
keywords = {Approximate entropy, Balance, Balancing, Biomechanics, BIOPHYSICS, Concussion, Entropy, Linear measures, Nonlinear measure, ORTHOPEDICS, Outcome measures, postural stability, Sample entropy, Scoring systems},
pubstate = {published},
tppubtype = {article}
}
Herman, Daniel C; Zaremski, Jason L; Vincent, Heather K; Vincent, Kevin R
Effect of neurocognition and concussion on musculoskeletal injury risk Journal Article
In: Current Sports Medicine Reports, vol. 14, pp. 194–199, 2015, ISSN: 1537-890X.
Links | BibTeX | Tags: Biomechanics
@article{Herman2015,
title = {Effect of neurocognition and concussion on musculoskeletal injury risk},
author = {Herman, Daniel C and Zaremski, Jason L and Vincent, Heather K and Vincent, Kevin R},
doi = {10.1249/JSR.0000000000000157},
issn = {1537-890X},
year = {2015},
date = {2015-01-01},
journal = {Current Sports Medicine Reports},
volume = {14},
pages = {194--199},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Post, A; Blaine Hoshizaki, T
Rotational acceleration, brain tissue strain, and the relationship to concussion Journal Article
In: Journal of Biomechanical Engineering, vol. 137, pp. 1, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Post2015c,
title = {Rotational acceleration, brain tissue strain, and the relationship to concussion},
author = {Post, A and {Blaine Hoshizaki}, T},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {137},
pages = {1},
abstract = {The mechanisms of concussion have been investigated by many researchers using a variety of methods. However, there remains much debate over the relationships between head kinematics from an impact and concussion. This review presents the links between research conducted in different disciplines to better understand the relationship between linear and rotational acceleration and brain strains that have been postulated as the root cause of concussion. These concepts are important when assigning performance variables for helmet development, car design, and protective innovation research.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Tong, D C; Winter, T J; Jin, J; Bennett, A C; Waddell, J N
Quantification of subconcussive impact forces to the head using a forensic model Journal Article
In: Journal of Clinical Neuroscience, vol. 22, pp. 747–751, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Tong2015,
title = {Quantification of subconcussive impact forces to the head using a forensic model},
author = {Tong, D C and Winter, T J and Jin, J and Bennett, A C and Waddell, J N},
year = {2015},
date = {2015-01-01},
journal = {Journal of Clinical Neuroscience},
volume = {22},
pages = {747--751},
address = {Tong,D C. Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dunedin 9010, New Zealand. Electronic address: darryl.tong@otago.ac.nz. Winter,T J. Sir John Walsh Research Institute, University of Otago, 310 Great King Street, Dun},
abstract = {Concussive and subconcussive head injury is a global phenomenon that affects millions of people each year. Concussive injury has been extensively studied in sport, which has led to a greater understanding of the biomechanical forces involved and guidelines aimed at preventing athletes from playing while concussed. Subconcussive forces by definition do not meet the threshold for concussion but nonetheless may have significant long term consequences due to the repetitive pattern of injury to the head. Quantifying these impact forces using a forensic head model provides the groundwork for future studies by establishing a range or threshold of subconcussive impact forces that could be correlated with clinical assessments. The use of a forensic head model has distinct advantages in terms of ethics and safety.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Iraji, A; Benson, R R; Welch, R D; O'Neil, B J; Woodard, J L; Ayaz, S I; Kulek, A; Mika, V; Medado, P; Soltanian-Zadeh, H; Liu, T; Haacke, E M; Kou, Z
Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 1031–1045, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Iraji2015,
title = {Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses},
author = {Iraji, A and Benson, R R and Welch, R D and O'Neil, B J and Woodard, J L and Ayaz, S I and Kulek, A and Mika, V and Medado, P and Soltanian-Zadeh, H and Liu, T and Haacke, E M and Kou, Z},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {1031--1045},
address = {Iraji,Armin. 1 Department of Biomedical Engineering, Wayne State University , Detroit, Michigan. Benson,Randall R. 2 Center for Neurologic Studies , Novi, Michigan. Welch,Robert D. 3 Department of Emergency Medicine, Wayne State University , Detroit, Mich},
abstract = {Mild traumatic brain injury (mTBI) accounts for more than 1 million emergency visits each year. Most of the injured stay in the emergency department for a few hours and are discharged home without a specific follow-up plan because of their negative clinical structural imaging. Advanced magnetic resonance imaging (MRI), particularly functional MRI (fMRI), has been reported as being sensitive to functional disturbances after brain injury. In this study, a cohort of 12 patients with mTBI were prospectively recruited from the emergency department of our local Level-1 trauma center for an advanced MRI scan at the acute stage. Sixteen age- and sex-matched controls were also recruited for comparison. Both group-based and individual-based independent component analysis of resting-state fMRI (rsfMRI) demonstrated reduced functional connectivity in both posterior cingulate cortex (PCC) and precuneus regions in comparison with controls, which is part of the default mode network (DMN). Further seed-based analysis confirmed reduced functional connectivity in these two regions and also demonstrated increased connectivity between these regions and other regions of the brain in mTBI. Seed-based analysis using the thalamus, hippocampus, and amygdala regions further demonstrated increased functional connectivity between these regions and other regions of the brain, particularly in the frontal lobe, in mTBI. Our data demonstrate alterations of multiple brain networks at the resting state, particularly increased functional connectivity in the frontal lobe, in response to brain concussion at the acute stage. Resting-state functional connectivity of the DMN could serve as a potential biomarker for improved detection of mTBI in the acute setting.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Ji, S; Zhao, W
A Pre-computed Brain Response Atlas for Instantaneous Strain Estimation in Contact Sports Journal Article
In: Annals of Biomedical Engineering, vol. 43, pp. 1877–1895, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Ji2015,
title = {A Pre-computed Brain Response Atlas for Instantaneous Strain Estimation in Contact Sports},
author = {Ji, S and Zhao, W},
year = {2015},
date = {2015-01-01},
journal = {Annals of Biomedical Engineering},
volume = {43},
pages = {1877--1895},
address = {Ji,Songbai. Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA, Songbai.Ji@Dartmouth.edu.},
abstract = {Finite element models of the human head play an important role in investigating the mechanisms of traumatic brain injury, including sports concussion. A critical limitation, however, is that they incur a substantial computational cost to simulate even a single impact. Therefore, current simulation schemes significantly hamper brain injury studies based on model-estimated tissue-level responses. In this study, we present a pre-computed brain response atlas (pcBRA) to substantially increase the simulation efficiency in estimating brain strains using isolated rotational acceleration impulses parameterized with four independent variables (peak magnitude and duration, and rotational axis azimuth and elevation angles) with values determined from on-field measurements. Using randomly generated testing datasets, the partially established pcBRA achieved a 100% success rate in interpolation based on element-wise differences in accumulated peak strain ([Formula: see text]) according to a "double-10%" criterion or average regional [Formula: see text] in generic regions and the corpus callosum. A similar performance was maintained in extrapolation. The pcBRA performance was further successfully validated against directly simulated responses from two independently measured typical real-world rotational profiles. The computational cost to estimate element-wise whole-brain or regional [Formula: see text] was 6 s and \<0.01 s, respectively, vs. $sim$50 min directly simulating a 40 ms impulse. These findings suggest the pcBRA could substantially increase the throughput in impact simulation without significant loss of accuracy from the estimation itself and, thus, its potential to accelerate the exploration of the mechanisms of sports concussion in general. If successful, the pcBRA may also become a diagnostic adjunct in conjunction with sensors that measure head impact kinematics on the field to objectively monitor and identify tissue-level brain trauma in real-time for "return-to-play" decision-making on the sideline.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Post, A; Kendall, M; Koncan, D; Cournoyer, J; Blaine Hoshizaki, T; Gilchrist, M D; Brien, S; Cusimano, M D; Marshall, S
Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling Journal Article
In: Journal of the Mechanical Behavior of Biomedical Materials, vol. 41, pp. 325–335, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Post2015,
title = {Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling},
author = {Post, A and Kendall, M and Koncan, D and Cournoyer, J and {Blaine Hoshizaki}, T and Gilchrist, M D and Brien, S and Cusimano, M D and Marshall, S},
year = {2015},
date = {2015-01-01},
journal = {Journal of the Mechanical Behavior of Biomedical Materials},
volume = {41},
pages = {325--335},
address = {Post,Andrew. Human Kinetics, University of Ottawa, Ottawa, ON, Canada K1N 6N5. Electronic address: apost@uottawa.ca. Kendall,Marshall. Human Kinetics, University of Ottawa, Ottawa, ON, Canada K1N 6N5. Koncan,David. Human Kinetics, University of Ottawa, Ot},
abstract = {Concussions occur 1.7 million times a year in North America, and account for approximately 75% of all traumatic brain injuries (TBI). Concussions usually cause transient symptoms but 10 to 20% of patients can have symptoms that persist longer than a month. The purpose of this research was to use reconstructions and finite element modeling to determine the brain tissue stresses and strains that occur in impacts that led to persistent post concussive symptoms (PCS) in hospitalized patients. A total of 21 PCS patients had their head impacts reconstructed using computational, physical and finite element methods. The dependent variables measured were maximum principal strain, von Mises stress (VMS), strain rate, and product of strain and strain rate. For maximum principal strain alone there were large regions of brain tissue incurring 30 to 40% strain. This large field of strain was also evident when using strain rate, product of strain and strain rate. In addition, VMS also showed large magnitudes of stress throughout the cerebrum tissues. The distribution of strains throughout the brain tissues indicated peak responses were always present in the grey matter (0.481), with the white matter showing significantly lower strains (0.380) (p\<0.05). The impact conditions of the PCS cases were severe in nature, with impacts against non-compliant surfaces (concrete, steel, ice) resulting in higher brain deformation. PCS biomechanical parameters were shown to fit between those that have been shown to cause transient post concussive symptoms and those that lead to actual pathologic damage like contusion, however, values of all metrics were characterized by large variance and high average responses. This data supports the theory that there exists a progressive continuum of impacts that lead to a progressive continuum of related severity of injury from transient symptoms to pathological damage.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Meier, T B; Bellgowan, P S; Singh, R; Kuplicki, R; Polanski, D W; Mayer, A R
Recovery of cerebral blood flow following sports-related concussion Journal Article
In: JAMA Neurology, vol. 72, pp. 530–538, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Meier2015,
title = {Recovery of cerebral blood flow following sports-related concussion},
author = {Meier, T B and Bellgowan, P S and Singh, R and Kuplicki, R and Polanski, D W and Mayer, A R},
year = {2015},
date = {2015-01-01},
journal = {JAMA Neurology},
volume = {72},
pages = {530--538},
address = {Meier,Timothy B. The Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico2Laureate Institute for Brain Research, Tulsa, Oklahoma. Bellgowan,Patrick S F. Laureate Institute for Brain Research, Tulsa, Oklah},
abstract = {IMPORTANCE: Animal models suggest that reduced cerebral blood flow (CBF) is one of the most enduring physiological deficits following concussion. Despite this, longitudinal studies documenting serial changes in regional CBF following human concussion have yet to be performed. OBJECTIVE: To longitudinally assess the recovery of CBF in a carefully selected sample of collegiate athletes and compare time course of CBF recovery with that of cognitive and behavioral symptoms. DESIGN, SETTING, AND PARTICIPANTS: A cohort of collegiate football athletes (N = 44) participated in this mixed longitudinal and cross-sectional study at a private research institute specializing in neuroimaging between March 2012 and December 2013. Serial imaging occurred approximately 1 day, 1 week, and 1 month postconcussion for a subset of participants (n = 17). All athletes reported no premorbid mood disorders, anxiety disorders, substance abuse, or alcohol abuse. MAIN OUTCOMES AND MEASURES: Arterial spin labeling magnetic resonance imaging was used to collect voxelwise relative CBF at each visit. Neuropsychiatric evaluations and a brief cognitive screen were also performed at all 3 points. Clinicians trained in sports medicine provided an independent measure of real-world concussion outcome (ie, number of days withheld from competition). RESULTS: The results indicated both cognitive (simple reaction time) and neuropsychiatric symptoms at 1 day postinjury that resolved at either 1 week (cognitive; P \<.005) or 1 month (neuropsychiatric; P \<.005) postinjury. Imaging data suggested both cross-sectional (ie, healthy vs concussed athletes; P \<.05) and longitudinal (1 day and 1 week vs 1 month postinjury; P \<.001) evidence of CBF recovery in the right insular and superior temporal cortex. Importantly, CBF in the dorsal midinsular cortex was both decreased at 1 month postconcussion in slower-to-recover athletes (t11 = 3.45; P =.005) and was inversely related to the magnitude of initial psychiatric symptoms (Hamilton Depression Scale: r = -0.64},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Kerr, Z Y; Littleton, A C; Cox, L M; DeFreese, J D; Varangis, E; Lynall, R C; Schmidt, J D; Marshall, S W; Guskiewicz, K M
Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 1083–1089, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Kerr2015ab,
title = {Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate},
author = {Kerr, Z Y and Littleton, A C and Cox, L M and DeFreese, J D and Varangis, E and Lynall, R C and Schmidt, J D and Marshall, S W and Guskiewicz, K M},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {1083--1089},
address = {Kerr,Zachary Y. 1 The Datalys Center for Sports Injury Research and Prevention, Indianapolis Indiana. Kerr,Zachary Y. 2 Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, University of North Carolina , Chapel Hill, North Carolina. Kerr,},
abstract = {Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information related to primary position played and participation in games and practice contacts during the pre-season, regular season, and post-season of each year of their high school, college, and professional football careers. Spring football for college was also included. We calculated contact exposure estimates for 64 former football players (n=32 college football only},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Rousseau, P; Hoshizaki, T B
Defining the effective impact mass of elbow and shoulder strikes in ice hockey Journal Article
In: Sports Biomechanics, vol. 14, pp. 57–67, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Rousseau2015,
title = {Defining the effective impact mass of elbow and shoulder strikes in ice hockey},
author = {Rousseau, P and Hoshizaki, T B},
year = {2015},
date = {2015-01-01},
journal = {Sports Biomechanics},
volume = {14},
pages = {57--67},
address = {Rousseau,Philippe. a Neurotrauma Impact Science Laboratory, Faculty of Health Sciences , University of Ottawa , Ottawa , ON , Canada.},
abstract = {Reconstruction of real-life events can be used to investigate the relationship between the mechanical parameters of the impact and concussion risk. Striking mass has typically been approximated as being the mass of the body part coming into contact with the head without accounting for the force applied by the striking athlete. Thus, the purpose of this study was to measure the effective impact mass of three common striking techniques in ice hockey. Fifteen participants were instructed to strike a suspended 50th percentile Hybrid III headform at least three times with their elbow or shoulder. Effective impact mass was calculated by measuring the change in velocity of the player and the headform. Mean effective impact mass for the extended elbow, tucked-in elbow, and shoulder check conditions were 4.8, 3.0, and 12.9 kg, respectively. Peak linear accelerations were lower than the values associated with concussion in American football which could be a reflection of the methodology used in this study as well as inherent differences between both sports.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Crisco, J J; Costa, L; Rich, R; Schwartz, J B; Wilcox, B
Surrogate headform accelerations associated with stick checks in girls' lacrosse Journal Article
In: Journal of Applied Biomechanics, vol. 31, pp. 122–127, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Crisco2015,
title = {Surrogate headform accelerations associated with stick checks in girls' lacrosse},
author = {Crisco, J J and Costa, L and Rich, R and Schwartz, J B and Wilcox, B},
year = {2015},
date = {2015-01-01},
journal = {Journal of Applied Biomechanics},
volume = {31},
pages = {122--127},
address = {Crisco,Joseph J. Bioengineering Laboratory, Department of Orthopaedics, Warren Alpert Medical School of Brown University, and Rhode Island Hospital, Providence, RI.},
abstract = {Girls' lacrosse is fundamentally a different sport than boys' lacrosse, and girls are not required to wear protective headgear. Recent epidemiological studies have found that stick checks are the leading cause of concussion injury in girls' lacrosse. The purpose of this study was to determine stick check speeds and estimate the head acceleration associated with direct checks to the head. In addition, we briefly examine if commercially available headgear can mitigate the accelerations. Seven (n = 7) experienced female lacrosse players checked, with varying severity, a NOSCAE and an ASTM headform. Stick speed at impact and the associated peak linear accelerations of the headform were recorded. The NOCSAE headform was fitted with four commercially available headgear and similar stick impact testing was performed. The median stick impact speed was 8.1 m/s and 777 deg/s. At these speeds, peak linear acceleration was approximately 60g. Three out of the four headgear significantly reduced the peak linear acceleration when compared with the bare headform. These data serve as baseline for understanding the potential mechanism and reduction of concussions from stick impacts in girls' lacrosse.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Oeur, R A; Karton, C; Post, A; Rousseau, P; Hoshizaki, T B; Marshall, S; Brien, S E; Smith, A; Cusimano, M D; Gilchrist, M D
In: Journal of Neurosurgery, vol. 123, no. 2, pp. 415–422, 2015.
Abstract | Links | BibTeX | Tags: accident, Accident reconstruction, accidental injury, Accidents, Adolescent, adult, Article, Biomechanical Phenomena, Biomechanics, brain, brain concussion, brain stem, brain tissue, Cerebellum, clinical article, comparative study, Concussion, controlled study, Female, finite element analysis, Finite element modelling, gray matter, Hematoma, human, Humans, Hybrid iii headform, injury severity, laboratory test, Male, Mechanical, mechanical stress, middle aged, pathology, Pathophysiology, Persistent postconcussive symptoms, PHYSIOLOGY, Post Hoc Analysis, Post-Concussion Syndrome, postconcussion syndrome, priority journal, shear stress, simulation, SPORTS medicine, STATISTICAL significance, Stress, stress strain relationship, Subdural, subdural hematoma, traumatic brain injury, white matter, Young Adult
@article{Oeur2015,
title = {A comparison of head dynamic response and brain tissue stress and strain using accident reconstructions for concussion, concussion with persistent postconcussive symptoms, and subdural hematoma},
author = {Oeur, R A and Karton, C and Post, A and Rousseau, P and Hoshizaki, T B and Marshall, S and Brien, S E and Smith, A and Cusimano, M D and Gilchrist, M D},
doi = {10.3171/2014.10.JNS14440},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurosurgery},
volume = {123},
number = {2},
pages = {415--422},
abstract = {Object Concussions typically resolve within several days, but in a few cases the symptoms last for a month or longer and are termed persistent postconcussive symptoms (PPCS). These persisting symptoms may also be associated with more serious brain trauma similar to subdural hematoma (SDH). The objective of this study was to investigate the head dynamic and brain tissue responses of injury reconstructions resulting in concussion, PPCS, and SDH. Methods Reconstruction cases were obtained from sports medicine clinics and hospitals. All subjects received a direct blow to the head resulting in symptoms. Those symptoms that resolved in 9 days or fewer were defined as concussions (n = 3). Those with symptoms lasting longer than 18 months were defined as PPCS (n = 3), and 3 patients presented with SDHs (n = 3). A Hybrid III headform was used in reconstruction to obtain linear and rotational accelerations of the head. These dynamic response data were then input into the University College Dublin Brain Trauma Model to calculate maximum principal strain and von Mises stress. A Kruskal-Wallis test followed by Tukey post hoc tests were used to compare head dynamic and brain tissue responses between injury groups. Statistical significance was set at p \< 0.05. Results A significant difference was identified for peak resultant linear and rotational acceleration between injury groups. Post hoc analyses revealed the SDH group had higher linear and rotational acceleration responses (316 g and 23,181 rad/sec2, respectively) than the concussion group (149 g and 8111 rad/sec2, respectively; p \< 0.05). No significant differences were found between groups for either brain tissue measures of maximum principal strain or von Mises stress. Conclusions The reconstruction of accidents resulting in a concussion with transient symptoms (low severity) and SDHs revealed a positive relationship between an increase in head dynamic response and the risk for more serious brain injury. This type of relationship was not found for brain tissue stress and strain results derived by finite element analysis. Future research should be undertaken using a larger sample size to confirm these initial findings. Understanding the relationship between the head dynamic and brain tissue response and the nature of the injury provides important information for developing strategies for injury prevention. © AANS, 2015.},
keywords = {accident, Accident reconstruction, accidental injury, Accidents, Adolescent, adult, Article, Biomechanical Phenomena, Biomechanics, brain, brain concussion, brain stem, brain tissue, Cerebellum, clinical article, comparative study, Concussion, controlled study, Female, finite element analysis, Finite element modelling, gray matter, Hematoma, human, Humans, Hybrid iii headform, injury severity, laboratory test, Male, Mechanical, mechanical stress, middle aged, pathology, Pathophysiology, Persistent postconcussive symptoms, PHYSIOLOGY, Post Hoc Analysis, Post-Concussion Syndrome, postconcussion syndrome, priority journal, shear stress, simulation, SPORTS medicine, STATISTICAL significance, Stress, stress strain relationship, Subdural, subdural hematoma, traumatic brain injury, white matter, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Patton, D A; McIntosh, A S; Kleiven, S
In: Journal of Applied Biomechanics, vol. 31, no. 4, pp. 264–268, 2015.
Abstract | Links | BibTeX | Tags: Article, Biomechanics, brain, Brain Injury, brain region, clinical article, Concussion, corpus callosum, Damage detection, evaluation study, finite element analysis, Finite element head models, Finite element method, Finite element simulations, football, gray matter, Head Injuries, head injury, human, Intra-cranial pressure, intracranial pressure, investigative procedures, Maximum principal strain, mesencephalon, Modeling, Models, Numerical reconstruction, Qualitative observations, Sport, sport injury, Sports, Strain and strain rates, Strain rate, Stress, thalamus, Tissue, tissue level
@article{Patton2015,
title = {The biomechanical determinants of concussion: Finite element simulations to investigate tissue-level predictors of injury during sporting impacts to the unprotected head},
author = {Patton, D A and McIntosh, A S and Kleiven, S},
doi = {10.1123/jab.2014-0223},
year = {2015},
date = {2015-01-01},
journal = {Journal of Applied Biomechanics},
volume = {31},
number = {4},
pages = {264--268},
abstract = {Biomechanical studies of concussions have progressed from qualitative observations of head impacts to physical and numerical reconstructions, direct impact measurements, and finite element analyses. Supplementary to a previous study, which investigated maximum principal strain, the current study used a detailed finite element head model to simulate unhelmeted concussion and no-injury head impacts and evaluate the effectiveness of various tissue-level brain injury predictors: strain rate, product of strain and strain rate, cumulative strain damage measure, von Mises stress, and intracranial pressure. Von Mises stress was found to be the most effective predictor of concussion. It was also found that the thalamus and corpus callosum were brain regions with strong associations with concussion. Tentative tolerance limits for tissue-level predictors were proposed in an attempt to broaden the understanding of unhelmeted concussions. For the thalamus, tolerance limits were proposed for a 50% likelihood of concussion: 2.24 kPa, 24.0 s-1, and 2.49 s-1 for von Mises stress, strain rate, and the product of strain and strain rate, respectively. For the corpus callosum, tolerance limits were proposed for a 50% likelihood of concussion: 3.51 kPa, 25.1 s-1, and 2.76 s-1 for von Mises stress, strain rate, and the product of strain and strain rate, respectively. © 2015 Human Kinetics, Inc.},
keywords = {Article, Biomechanics, brain, Brain Injury, brain region, clinical article, Concussion, corpus callosum, Damage detection, evaluation study, finite element analysis, Finite element head models, Finite element method, Finite element simulations, football, gray matter, Head Injuries, head injury, human, Intra-cranial pressure, intracranial pressure, investigative procedures, Maximum principal strain, mesencephalon, Modeling, Models, Numerical reconstruction, Qualitative observations, Sport, sport injury, Sports, Strain and strain rates, Strain rate, Stress, thalamus, Tissue, tissue level},
pubstate = {published},
tppubtype = {article}
}
Zaremski, Jason L; Herman, Daniel C; Clugston, James R; Hurley, Robert W; Ahn, Andrew H
Occipital neuralgia as a sequela of sports concussion: a case series and review of the literature Journal Article
In: Current Sports Medicine Reports, vol. 14, pp. 16–19, 2015, ISSN: 1537-890X.
Links | BibTeX | Tags: Biomechanics
@article{Zaremski2015,
title = {Occipital neuralgia as a sequela of sports concussion: a case series and review of the literature},
author = {Zaremski, Jason L and Herman, Daniel C and Clugston, James R and Hurley, Robert W and Ahn, Andrew H},
doi = {10.1249/JSR.0000000000000121},
issn = {1537-890X},
year = {2015},
date = {2015-01-01},
journal = {Current Sports Medicine Reports},
volume = {14},
pages = {16--19},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Doshi, H; Wiseman, N; Liu, J; Wang, W; Welch, R D; O'Neil, B J; Zuk, C; Wang, X; Mika, V; Szaflarski, J P; Haacke, E M; Kou, Z
Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage Journal Article
In: PLoS ONE, vol. 10, pp. e0118061, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Doshi2015,
title = {Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage},
author = {Doshi, H and Wiseman, N and Liu, J and Wang, W and Welch, R D and O'Neil, B J and Zuk, C and Wang, X and Mika, V and Szaflarski, J P and Haacke, E M and Kou, Z},
year = {2015},
date = {2015-01-01},
journal = {PLoS ONE},
volume = {10},
pages = {e0118061},
address = {Doshi,Hardik. Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America. Wiseman,Natalie. Department of Psychiatry and Behavioral Neurosciences Translational Neuroscience Program, Wayne State University Scho},
abstract = {Mild traumatic brain injury (mTBI) is a significant public health care burden in the United States. However, we lack a detailed understanding of the pathophysiology following mTBI and its relation to symptoms and recovery. With advanced magnetic resonance imaging (MRI), we can investigate brain perfusion and oxygenation in regions known to be implicated in symptoms, including cortical gray matter and subcortical structures. In this study, we assessed 14 mTBI patients and 18 controls with susceptibility weighted imaging and mapping (SWIM) for blood oxygenation quantification. In addition to SWIM, 7 patients and 12 controls had cerebral perfusion measured with arterial spin labeling (ASL). We found increases in regional cerebral blood flow (CBF) in the left striatum, and in frontal and occipital lobes in patients as compared to controls (p = 0.01, 0.03, 0.03 respectively). We also found decreases in venous susceptibility, indicating increases in venous oxygenation, in the left thalamostriate vein and right basal vein of Rosenthal (p = 0.04 in both). mTBI patients had significantly lower delayed recall scores on the standardized assessment of concussion, but neither susceptibility nor CBF measures were found to correlate with symptoms as assessed by neuropsychological testing. The increased CBF combined with increased venous oxygenation suggests an increase in cerebral blood flow that exceeds the oxygen demand of the tissue, in contrast to the regional hypoxia seen in more severe TBI. This may represent a neuroprotective response following mTBI, which warrants further investigation.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Seifert, Tad; Shipman, Victoria
The Pathophysiology of Sports Concussion Journal Article
In: Current Pain & Headache Reports, vol. 19, pp. 513, 2015, ISSN: 1531-3433.
Abstract | Links | BibTeX | Tags: Biomechanics
@article{Seifert2015,
title = {The Pathophysiology of Sports Concussion},
author = {Seifert, Tad and Shipman, Victoria},
doi = {10.1007/s11916-015-0513-0},
issn = {1531-3433},
year = {2015},
date = {2015-01-01},
journal = {Current Pain \& Headache Reports},
volume = {19},
pages = {513},
abstract = {During concussion, the brain is exposed to rapid acceleration, deceleration, and rotational forces, resulting in the stretching and distortion of neural structures. This produces in an injury of transient neurological dysfunction, as evidenced by the clinical symptomatology. It is now evident that recurrent head trauma is also associated with the development of some chronic neurodegenerative disorders. Despite increased awareness of concussion over the past decade, large voids remain in our understanding of its pathophysiology. Prospective longitudinal studies are needed to better understand the underlying biological mechanism of acute concussive injury as it relates to chronic neuropathology.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Pang, K C; Sinha, S; Avcu, P; Roland, J J; Nadpara, N; Pfister, B; Long, M; Santhakumar, V; Servatius, R J
Long-lasting suppression of acoustic startle response after mild traumatic brain injury Journal Article
In: Journal of Neurotrauma, vol. 32, pp. 801–810, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Pang2015,
title = {Long-lasting suppression of acoustic startle response after mild traumatic brain injury},
author = {Pang, K C and Sinha, S and Avcu, P and Roland, J J and Nadpara, N and Pfister, B and Long, M and Santhakumar, V and Servatius, R J},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
pages = {801--810},
address = {Pang,Kevin C H. 1Neurobehavioral Research Lab, Department of Veteran Affairs Medical Center-New Jersey Health Care System, East Orange, New Jersey. Pang,Kevin C H. 2Stress and Motivated Behavior Institute, New Jersey Medical School-Rutgers Biomedical and},
abstract = {Acoustic startle response (ASR) is a defensive reflex that is largely ignored unless greatly exaggerated. ASR is suppressed after moderate and severe traumatic brain injury (TBI), but the effect of mild TBI (mTBI) on ASR has not been investigated. Because the neural circuitry for ASR resides in the pons in all mammals, ASR may be a good measure of brainstem function after mTBI. The present study assessed ASR in Sprague-Dawley rats after mTBI using lateral fluid percussion and compared these effects to those on spatial working memory. mTBI caused a profound, long-lasting suppression of ASR. Both probability of emitting a startle and startle amplitude were diminished. ASR suppression was observed as soon as 1 day after injury and remained suppressed for the duration of the study (21 days after injury). No indication of recovery was observed. mTBI also impaired spatial working memory. In contrast to the suppression of ASR, working memory impairment was transient; memory was impaired 1 and 7 days after injury, but recovered by 21 days. The long-lasting suppression of ASR suggests long-term dysfunction of brainstem neural circuits at a time when forebrain neural circuits responsible for spatial working memory have recovered. These results have important implications for return-to-activity decisions because recovery of cognitive impairments plays an important role in these decisions.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Stemper, B D; Shah, A S; Pintar, F A; McCrea, M; Kurpad, S N; Glavaski-Joksimovic, A; Olsen, C; Budde, M D
Head Rotational Acceleration Characteristics Influence Behavioral and Diffusion Tensor Imaging Outcomes Following Concussion Journal Article
In: Annals of Biomedical Engineering, vol. 43, no. 5, pp. 1071–1088, 2015.
Abstract | Links | BibTeX | Tags: Acceleration, Accidents, BEHAVIORAL assessment, Behavioral assessments, Behavioral outcomes, Biomechanics, brain, Cognitive deficits, Diffusion, Diffusion Tensor Imaging, Diffusion tensor imaging (DTI), fractional anisotropy, Full factorial design, Magnetic Resonance Imaging, Microstructure, Motor vehicle crashes, neuroimaging, Rats, Rotational acceleration, Tensors, Traumatic Brain Injuries, Traumatic brain injury (mTBI)
@article{Stemper2015,
title = {Head Rotational Acceleration Characteristics Influence Behavioral and Diffusion Tensor Imaging Outcomes Following Concussion},
author = {Stemper, B D and Shah, A S and Pintar, F A and McCrea, M and Kurpad, S N and Glavaski-Joksimovic, A and Olsen, C and Budde, M D},
doi = {10.1007/s10439-014-1171-9},
year = {2015},
date = {2015-01-01},
journal = {Annals of Biomedical Engineering},
volume = {43},
number = {5},
pages = {1071--1088},
abstract = {A majority of traumatic brain injuries (TBI) in motor vehicle crashes and sporting environments are mild and caused by high-rate acceleration of the head. For injuries caused by rotational acceleration, both magnitude and duration of the acceleration pulse were shown to influence injury outcomes. This study incorporated a unique rodent model of rotational acceleration-induced mild TBI (mTBI) to quantify independent effects of magnitude and duration on behavioral and neuroimaging outcomes. Ninety-two Sprague\textendashDawley rats were exposed to head rotational acceleration at peak magnitudes of 214 or 350 krad/s2 and acceleration pulse durations of 1.6 or 3.4 ms in a full factorial design. Rats underwent a series of behavioral tests including the Composite Neuroscore (CN), Elevated Plus Maze (EPM), and Morris Water Maze (MWM). Ex vivo diffusion tensor imaging (DTI) of the fixed brains was conducted to assess the effects of rotational injury on brain microstructure as revealed by the parameter fractional anisotropy (FA). While the injury did not cause significant locomotor or cognitive deficits measured with the CN and MWM, respectively, a main effect of duration was consistently observed for the EPM. Increased duration caused significantly greater activity and exploratory behaviors measured as open arm time and number of arm changes. DTI demonstrated significant effects of both magnitude and duration, with the FA of the amygdala related to both the magnitude and duration. Increased duration also caused FA changes at the interface of gray and white matter. Collectively, the findings demonstrate that the consequences of rotational acceleration mTBI were more closely associated with duration of the rotational acceleration impulse, which is often neglected as an independent factor, and highlight the need for animal models of TBI with strong biomechanical foundations to associate behavioral outcomes with brain microstructure. © 2014, Biomedical Engineering Society (Outside the U.S.).},
keywords = {Acceleration, Accidents, BEHAVIORAL assessment, Behavioral assessments, Behavioral outcomes, Biomechanics, brain, Cognitive deficits, Diffusion, Diffusion Tensor Imaging, Diffusion tensor imaging (DTI), fractional anisotropy, Full factorial design, Magnetic Resonance Imaging, Microstructure, Motor vehicle crashes, neuroimaging, Rats, Rotational acceleration, Tensors, Traumatic Brain Injuries, Traumatic brain injury (mTBI)},
pubstate = {published},
tppubtype = {article}
}
Franck, J A; Blume, J; Crisco, J J; Franck, C
Extracting Time-Accurate Acceleration Vectors From Nontrivial Accelerometer Arrangements Journal Article
In: Journal of Biomechanical Engineering, vol. 137, pp. 1, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Franck2015,
title = {Extracting Time-Accurate Acceleration Vectors From Nontrivial Accelerometer Arrangements},
author = {Franck, J A and Blume, J and Crisco, J J and Franck, C},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {137},
pages = {1},
abstract = {Sports-related concussions are of significant concern in many impact sports, and their detection relies on accurate measurements of the head kinematics during impact. Among the most prevalent recording technologies are videography, and more recently, the use of single-axis accelerometers mounted in a helmet, such as the HIT system. Successful extraction of the linear and angular impact accelerations depends on an accurate analysis methodology governed by the equations of motion. Current algorithms are able to estimate the magnitude of acceleration and hit location, but make assumptions about the hit orientation and are often limited in the position and/or orientation of the accelerometers. The newly formulated algorithm presented in this manuscript accurately extracts the full linear and rotational acceleration vectors from a broad arrangement of six single-axis accelerometers directly from the governing set of kinematic equations. The new formulation linearizes the nonlinear centripetal acceleration term with a finite-difference approximation and provides a fast and accurate solution for all six components of acceleration over long time periods (\>250ms). The approximation of the nonlinear centripetal acceleration term provides an accurate computation of the rotational velocity as a function of time and allows for reconstruction of a multiple-impact signal. Furthermore, the algorithm determines the impact location and orientation and can distinguish between glancing, high rotational velocity impacts, or direct impacts through the center of mass. Results are shown for ten simulated impact locations on a headform geometry computed with three different accelerometer configurations in varying degrees of signal noise. Since the algorithm does not require simplifications of the actual impacted geometry, the impact vector, or a specific arrangement of accelerometer orientations, it can be easily applied to many impact investigations in which accurate kinematics need to be extracted from single-axis accelerometer data.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Alberts, J L; Hirsch, J R; Koop, M M; Schindler, D D; Kana, D E; Linder, S M; Campbell, S; Thota, A K
Using Accelerometer and Gyroscopic Measures to Quantify Postural Stability Journal Article
In: Journal of Athletic Training, vol. 50, pp. 578–588, 2015.
Abstract | BibTeX | Tags: Biomechanics
@article{Alberts2015a,
title = {Using Accelerometer and Gyroscopic Measures to Quantify Postural Stability},
author = {Alberts, J L and Hirsch, J R and Koop, M M and Schindler, D D and Kana, D E and Linder, S M and Campbell, S and Thota, A K},
year = {2015},
date = {2015-01-01},
journal = {Journal of Athletic Training},
volume = {50},
pages = {578--588},
address = {Alberts,Jay L. Department of Biomedical Engineering, Cleveland Clinic, OH; Alberts,Jay L. Center for Neurological Restoration, Cleveland Clinic, OH; Alberts,Jay L. Cleveland Clinic Concussion Center, Cleveland Clinic, OH; Alberts,Jay L. Cleveland Function},
abstract = {CONTEXT: Force platforms and 3-dimensional motion-capture systems provide an accurate method of quantifying postural stability. Substantial cost, space, time to administer, and need for trained personnel limit widespread use of biomechanical techniques in the assessment of postural stability in clinical or field environments. OBJECTIVE: To determine whether accelerometer and gyroscope data sampled from a consumer electronics device (iPad2) provide sufficient resolution of center-of-gravity (COG) movements to accurately quantify postural stability in healthy young people. DESIGN: Controlled laboratory study. SETTING: Research laboratory in an academic medical center. PATIENTS OR OTHER PARTICIPANTS: A total of 49 healthy individuals (age = 19.5 +/- 3.1 years},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Giordano, C; Kleiven, S
Evaluation of Axonal Strain as a Predictor for Mild Traumatic Brain Injuries Using Finite Element Modeling Journal Article
In: Stapp Car Crash Journal, vol. 58, pp. 29–61, 2014.
Abstract | BibTeX | Tags: Biomechanics
@article{Giordano2014,
title = {Evaluation of Axonal Strain as a Predictor for Mild Traumatic Brain Injuries Using Finite Element Modeling},
author = {Giordano, C and Kleiven, S},
year = {2014},
date = {2014-01-01},
journal = {Stapp Car Crash Journal},
volume = {58},
pages = {29--61},
address = {Giordano,Chiara. KTH - Royal Institute of Technology, School of Technology and Health, Neuronic Engineering, Alfred Nobels Alle 10, 141 52 Huddinge, Sweden. Kleiven,Svein. KTH - Royal Institute of Technology, School of Technology and Health, Neuronic Engi},
abstract = {Finite element (FE) models are often used to study the biomechanical effects of traumatic brain injury (TBI). Measures based on mechanical responses, such as principal strain or invariants of the strain tensor, are used as a metric to predict the risk of injury. However, the reliability of inferences drawn from these models depends on the correspondence between the mechanical measures and injury data, as well as the establishment of accurate thresholds of tissue injury. In the current study, a validated anisotropic FE model of the human head is used to evaluate the hypothesis that strain in the direction of fibers (axonal strain) is a better predictor of TBI than maximum principal strain (MPS), anisotropic equivalent strain (AESM) and cumulative strain damage measure (CSDM). An analysis of head kinematics-based metrics, such as head injury criterion (HIC) and brain injury criterion (BrIC), is also provided. Logistic regression analysis is employed to compare binary injury data (concussion/no concussion) with continuous strain/kinematics data. The threshold corresponding to 50% of injury probability is determined for each parameter. The predictive power (area under the ROC curve, AUC) is calculated from receiver operating characteristic (ROC) curve analysis. The measure with the highest AUC is considered to be the best predictor of mTBI. Logistic regression shows a statistical correlation between all the mechanical predictors and injury data for different regions of the brain. Peaks of axonal strain have the highest AUC and determine a strain threshold of 0.07 for corpus callosum and 0.15 for the brainstem, in agreement with previously experimentally derived injury thresholds for reversible axonal injury. For a data set of mild TBI from the national football league, the strain in the axonal direction is found to be a better injury predictor than MPS, AESM, CSDM, BrIC and HIC.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Daniel, R W; Rowson, S; Duma, S M
Head acceleration measurements in middle school football Journal Article
In: Biomedical Sciences Instrumentation, vol. 50, pp. 291–296, 2014.
Abstract | BibTeX | Tags: Biomechanics
@article{Daniel2014,
title = {Head acceleration measurements in middle school football},
author = {Daniel, R W and Rowson, S and Duma, S M},
year = {2014},
date = {2014-01-01},
journal = {Biomedical Sciences Instrumentation},
volume = {50},
pages = {291--296},
address = {Daniel,Ray W. Virginia Tech - Wake Forest University, Blacksburg.},
abstract = {Although youth football players account for approximately 70% of all football players, the majority of research investigating concussion in football has focused on adults. The objective of this study was to investigate the head impact exposure experienced by middle school football players between the ages of 12 and 14 years. Recruited players were equipped with helmets instrumented with accelerometer arrays for 5 games and 27 practices. Linear accelerations ranged from 10 g to 150 g and rotational accelerations ranged from 4 rad/s2 to 9019 rad/s2. The average player experienced 210 +/- 162 impacts while instrumented. The average player sustained a median impact of 21 +/- 1 g and 885 +/- 104 rad/s2, and a 95th percentile impact of 57 +/- 12 g and 2570 +/- 544 rad/s2. Data were then used to estimate a full middle school football seasons head impacexposure for comparisons. Both impact magnitude and impact location distributions were similar to past studies investigating head impacts in high school and collegiate football players. Middle school players experience a greater number of impacts during games than during practices, and the majority of impacts occurred to the front or rear of the helmet. With an increased understanding of the head impact exposure experienced by youth football players, measures can be implemented to better protect players.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Duhaime, A C
Response Journal Article
In: Journal of Neurosurgery, vol. 117, no. 6, pp. 1090–1091, 2012, ISBN: 0022-3085 1933-0693.
BibTeX | Tags: Accident prevention, Assessment & Testing, athlete, Biomechanics, brain concussion, Equipment, headache, Helmets, human, Neck pain, neurosurgery, Note, Post-Concussion, priority journal, sport injury, surgeon, symptom, Syndrome, traumatic brain injury, unconsciousness
@article{Duhaime2012,
title = {Response},
author = {Duhaime, A C},
isbn = {0022-3085
1933-0693},
year = {2012},
date = {2012-01-01},
journal = {Journal of Neurosurgery},
volume = {117},
number = {6},
pages = {1090--1091},
keywords = {Accident prevention, Assessment \& Testing, athlete, Biomechanics, brain concussion, Equipment, headache, Helmets, human, Neck pain, neurosurgery, Note, Post-Concussion, priority journal, sport injury, surgeon, symptom, Syndrome, traumatic brain injury, unconsciousness},
pubstate = {published},
tppubtype = {article}
}
Rowson, Steven; Duma, Stefan M; Beckwith, Jonathan G; Chu, Jeffrey J; Greenwald, Richard M; Crisco, Joseph J; Brolinson, P Gunnar; Duhaime, Ann-Christine; McAllister, Thomas W; Maerlender, Arthur C
Rotational head kinematics in football impacts: an injury risk function for concussion Journal Article
In: Annals of Biomedical Engineering, vol. 40, pp. 1–13, 2012.
Abstract | BibTeX | Tags: Biomechanics
@article{Rowson2012,
title = {Rotational head kinematics in football impacts: an injury risk function for concussion},
author = {Rowson, Steven and Duma, Stefan M and Beckwith, Jonathan G and Chu, Jeffrey J and Greenwald, Richard M and Crisco, Joseph J and Brolinson, P Gunnar and Duhaime, Ann-Christine and McAllister, Thomas W and Maerlender, Arthur C},
year = {2012},
date = {2012-01-01},
journal = {Annals of Biomedical Engineering},
volume = {40},
pages = {1--13},
address = {School of Biomedical Engineering \& Sciences, Virginia Tech-Wake Forest University, 440 ICTAS Building, Stanger St, Blacksburg, VA 24061, USA. srowson@vt.edu},
abstract = {Recent research has suggested a possible link between sports-related concussions and neurodegenerative processes, highlighting the importance of developing methods to accurately quantify head impact tolerance. The use of kinematic parameters of the head to predict brain injury has been suggested because they are indicative of the inertial response of the brain. The objective of this study is to characterize the rotational kinematics of the head associated with concussive impacts using a large head acceleration dataset collected from human subjects. The helmets of 335 football players were instrumented with accelerometer arrays that measured head acceleration following head impacts sustained during play, resulting in data for 300,977 sub-concussive and 57 concussive head impacts. The average sub-concussive impact had a rotational acceleration of 1230 rad/s(2) and a rotational velocity of 5.5 rad/s, while the average concussive impact had a rotational acceleration of 5022 rad/s(2) and a rotational velocity of 22.3 rad/s. An injury risk curve was developed and a nominal injury value of 6383 rad/s(2) associated with 28.3 rad/s represents 50% risk of concussion. These data provide an increased understanding of the biomechanics associated with concussion and they provide critical insight into injury mechanisms, human tolerance to mechanical stimuli, and injury prevention techniques.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Guskiewicz, Kevin M; Mihalik, Jason P
Biomechanics of sport concussion: quest for the elusive injury threshold Journal Article
In: Exercise & Sport Sciences Reviews, vol. 39, pp. 4–11, 2011.
Abstract | BibTeX | Tags: Biomechanics
@article{Guskiewicz2011a,
title = {Biomechanics of sport concussion: quest for the elusive injury threshold},
author = {Guskiewicz, Kevin M and Mihalik, Jason P},
year = {2011},
date = {2011-01-01},
journal = {Exercise \& Sport Sciences Reviews},
volume = {39},
pages = {4--11},
address = {Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, and Curriculum in Human Movement Science, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599, USA. gus@email.unc.edu},
abstract = {Previous concussion biomechanics research has relied heavily on the animal model or laboratory reconstruction of concussive injuries captured on video footage. Real-time data collection involves a novel approach to better understanding the medical issues related to sport concussion. Recent studies suggest that a concussive injury threshold is elusive and may, in fact, be irrelevant when predicting the clinical outcome.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Patton, D; McIntosh, A; Kleiven, S
Brain loading in concussive head impacts: implications for injury prevention Journal Article
In: British Journal of Sports Medicine, vol. 45, pp. 318, 2011.
Abstract | BibTeX | Tags: Biomechanics
@article{Patton2011,
title = {Brain loading in concussive head impacts: implications for injury prevention},
author = {Patton, D and McIntosh, A and Kleiven, S},
year = {2011},
date = {2011-01-01},
journal = {British Journal of Sports Medicine},
volume = {45},
pages = {318},
abstract = {Background Concussion is a prominent injury risk in sport, but the mechanisms that cause concussion are unclear. An important debate centres on the roles of angular and linear head acceleration in the mechanism of concussion. Resolving this debate is a prerequisite for developing injury prevention methods. Objective To estimate the brain loading patterns in a case series of concussive and no-injury head impacts. To assess the relative affects of linear and angular acceleration on brain loading and injury. Design Biomechanical analysis of head impacts using the validated KTH human head finite element model to analyse brain loading patterns in reconstructed head impacts. Setting Professional male unhelmeted contact football. Participants Biomechanical data from a previous case series study of 40 male football players (concussed and no-injury). Main outcome measurements Maximum principle strain, a predictor of injury, was measured in discrete brain locations. Results The highest maximum principle strains were recorded in both the white and grey matter of the cerebrum. Strains in all brain regions were similar across all three grades of concussion (Cantu Revised Concussion Grading Guidelines), but lower (33-47%) for no-injury cases. Concussion was most correlated with strains in the brainstem and thalamus. Angular, rather than linear, resultant accelerations correlated higher to strains in all regions of the brain. Angular accelerations in the coronal plane and linear accelerations directed inferiorly had the greatest correlation to concussion and loss of consciousness. For linear accelerations, those directed laterally and inferiorly were most correlated with strain. Angular accelerations in the coronal plane correlated highly with strains in the brainstem, thalamus, and midbrain. Angular accelerations in the transverse plane correlated highly with strains in the cerebrum and corpus callosum. Conclusion Brain loading differences were observed between concussion and no-injury cases. Angular acceleration may play a more important role in the mechanism of concussion than linear acceleration.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Almosnino, Sivan; Pelland, Lucie; Stevenson, Joan M
Retest reliability of force-time variables of neck muscles under isometric conditions Journal Article
In: Journal of Athletic Training, vol. 45, pp. 453–458, 2010.
Abstract | BibTeX | Tags: Biomechanics
@article{Almosnino2010,
title = {Retest reliability of force-time variables of neck muscles under isometric conditions},
author = {Almosnino, Sivan and Pelland, Lucie and Stevenson, Joan M},
year = {2010},
date = {2010-01-01},
journal = {Journal of Athletic Training},
volume = {45},
pages = {453--458},
address = {School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada.},
abstract = {CONTEXT: Proper conditioning of the neck muscles may play a role in reducing the risk of neck injury and, possibly, concussions in contact sports. However, the ability to reliably measure the force-time-based variables that might be relevant for this purpose has not been addressed. OBJECTIVE: To assess the between-days reliability of discrete force-time-based variables of neck muscles during maximal voluntary isometric contractions in 5 directions. DESIGN: Cohort study. SETTING: University research center. PATIENTS OR OTHER PARTICIPANTS: Twenty-six highly physically active men (age = 21.6 +/- 2.1 years},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Greenwald, Richard M; Gwin, Joseph T; Chu, Jeffrey J; Crisco, Joseph J
Head impact severity measures for evaluating mild traumatic brain injury risk exposure Journal Article
In: Neurosurgery, vol. 62, pp. 789–98; discussion 798, 2008.
Abstract | BibTeX | Tags: Biomechanics
@article{Greenwald2008,
title = {Head impact severity measures for evaluating mild traumatic brain injury risk exposure},
author = {Greenwald, Richard M and Gwin, Joseph T and Chu, Jeffrey J and Crisco, Joseph J},
year = {2008},
date = {2008-01-01},
journal = {Neurosurgery},
volume = {62},
pages = {789--98; discussion 798},
address = {Simbex, Lebanon, New Hampshire, USA.},
abstract = {OBJECTIVE: The aims of this study were to quantify the sensitivity of various biomechanical measures (linear acceleration, rotational acceleration, impact duration, and impact location) of head impact to the clinical diagnosis of concussion in United States football players and to develop a novel measure of head impact severity combining these measures into a single score that better predicts the incidence of concussion. METHODS: On-field head impact data were collected from 449 football players at 13 organizations (n = 289,916) using in-helmet systems of six single-axis accelerometers. Concussions were diagnosed by medical staff and later associated with impact data. Principal component analysis and a weighting coefficient based on impact location were used to transform correlated head impact measures into a new composite variable, weighted principal component score (wPCS). The predictive power of linear acceleration, rotational acceleration, head injury criterion, and wPCS was quantified using receiver operating characteristic curves. The null hypothesis, that a measure was no more predictive than guessing, was tested (alpha = 0.05). In addition, receiver operating characteristic curves for wPCS and classical measures were directly compared to test the hypothesis that wPCS was more predictive of concussion than were classic measures (alpha = 0.05). RESULTS: When all of the impacts were considered, every biomechanical measure evaluated was statistically more predictive of concussion than guessing (P \< 0.005). However, for the top 1 and 2% of impacts based on linear acceleration, a subset that consisted of 82% of all diagnosed concussions, only wPCS was significantly more predictive of concussion than guessing (P \< 0.03); when compared with each other, wPCS was more predictive of concussion than were classical measures for the top 1 and 2% of all of the data (P \< 0.04). CONCLUSION: A weighted combination of several biomechanical inputs, including impact location, is more predictive of concussion than a single biomechanical measure. This study is the first to the authors' knowledge to quantify improvements in the sensitivity of a biomechanical measure to incidence of concussion when impact location is considered.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Beckwith, Jonathan G; Chu, Jeffrey J; Greenwald, Richard M
Validation of a noninvasive system for measuring head acceleration for use during boxing competition Journal Article
In: Journal of Applied Biomechanics, vol. 23, pp. 238–244, 2007.
Abstract | BibTeX | Tags: Biomechanics
@article{Beckwith2007,
title = {Validation of a noninvasive system for measuring head acceleration for use during boxing competition},
author = {Beckwith, Jonathan G and Chu, Jeffrey J and Greenwald, Richard M},
year = {2007},
date = {2007-01-01},
journal = {Journal of Applied Biomechanics},
volume = {23},
pages = {238--244},
address = {Simbex, Lebanon, NH, USA.},
abstract = {Although the epidemiology and mechanics of concussion in sports have been investigated for many years, the biomechanical factors that contribute to mild traumatic brain injury remain unclear because of the difficulties in measuring impact events in the field. The purpose of this study was to validate an instrumented boxing headgear (IBH) that can be used to measure impact severity and location during play. The instrumented boxing headgear data were processed to determine linear and rotational acceleration at the head center of gravity, impact location, and impact severity metrics, such as the Head Injury Criterion (HIC) and Gadd Severity Index (GSI). The instrumented boxing headgear was fitted to a Hybrid III (HIII) head form and impacted with a weighted pendulum to characterize accuracy and repeatability. Fifty-six impacts over 3 speeds and 5 locations were used to simulate blows most commonly observed in boxing. A high correlation between the HIII and instrumented boxing headgear was established for peak linear and rotational acceleration (r2= 0.91), HIC (r2 = 0.88), and GSI (r2 = 0.89). Mean location error was 9.7 +/- 5.2 masculine. Based on this study, the IBH is a valid system for measuring head acceleration and impact location that can be integrated into training and competition.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Pearson, B C; Armitage, K R; Horner, C W M; Carpenter, R H S
Saccadometry: the possible application of latency distribution measurement for monitoring concussion Journal Article
In: British Journal of Sports Medicine, vol. 41, pp. 610–612, 2007.
Abstract | BibTeX | Tags: Biomechanics
@article{Pearson2007,
title = {Saccadometry: the possible application of latency distribution measurement for monitoring concussion},
author = {Pearson, B C and Armitage, K R and Horner, C W M and Carpenter, R H S},
year = {2007},
date = {2007-01-01},
journal = {British Journal of Sports Medicine},
volume = {41},
pages = {610--612},
address = {Department of Physiology, Development and Neuroscience, University of Cambridge, UK. bcp22@cam.ac.uk},
abstract = {Premature return to play after concussion may have debilitating or even fatal consequences. Computerised neuropsychological test batteries are widely used to monitor recovery, but none meet all specified criteria. One possible alternative is to measure saccadic reaction time or latency. Latency reflects the operation of cerebral decision mechanisms, and is strongly influenced by many agents that impair cortical function. A portable, micro-miniature device (saccadometer) was used to record the eye movements of amateur boxers before and after competitive bouts. Individual latency distributions were significantly affected after blows to the head, though the effects seemed to be reversible, with recovery over a few days. This quantitative, objective and easy to use technique should perhaps be deployed more widely to evaluate its potential in monitoring the effects of sports-related head injuries.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Zumsteg, Dominik; Wennberg, Richard; Gutling, Eva; Hess, Klaus
Whiplash and concussion: similar acute changes in middle-latency SEPs Journal Article
In: Canadian Journal of Neurological Sciences, vol. 33, pp. 379–386, 2006.
Abstract | BibTeX | Tags: Biomechanics
@article{Zumsteg2006,
title = {Whiplash and concussion: similar acute changes in middle-latency SEPs},
author = {Zumsteg, Dominik and Wennberg, Richard and Gutling, Eva and Hess, Klaus},
year = {2006},
date = {2006-01-01},
journal = {Canadian Journal of Neurological Sciences},
volume = {33},
pages = {379--386},
address = {Krembil Neuroscience Centre, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada.},
abstract = {OBJECTIVE: Middle-latency somatosensory evoked potentials (SEPs) following median nerve stimulation can provide a sensitive measure of cortical function. We sought to determine whether the mechanical forces of whiplash injury or concussion alter normal processing of middle-latency SEPs. METHODS: In a cross-sectional pilot study 20 subjects with whiplash were investigated (50% between 0.5-2 months and 50% between 6-41 months post injury) and compared to 83 healthy subjects using a standard middle-latency SEP procedure. In a subsequent prospective study subjects with either acute whiplash (n=13) or Grade 3 concussion (n=16) were investigated within 48 hours and again three months post injury. RESULTS: In the pilot study the middle-latency SEP component N60 was significantly increased in the ten subjects investigated within two months after whiplash. In contrast, the ten subjects examined more than six months after injury showed normal latencies. In the prospective study N60 latencies were increased after whiplash and concussion when tested within 48 hours of injury. At three months, latencies were improved though still significantly different from controls post whiplash and concussion. CONCLUSIONS: Both whiplash injury and concussion alter processing of the middle-latency SEP component N60 in the acute post traumatic period. The acute changes appear to normalize between three-six months post injury. The SEP similarities suggest that the overlapping clinical symptomatology post whiplash and concussion may reflect a similar underlying mechanism of rotational mild traumatic brain injury.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Mourouzis, C; Koumoura, F
Sports-related maxillofacial fractures: a retrospective study of 125 patients Journal Article
In: International Journal of Oral & Maxillofacial Surgery, vol. 34, pp. 635–638, 2005.
Abstract | BibTeX | Tags: Biomechanics
@article{Mourouzis2005,
title = {Sports-related maxillofacial fractures: a retrospective study of 125 patients},
author = {Mourouzis, C and Koumoura, F},
year = {2005},
date = {2005-01-01},
journal = {International Journal of Oral \& Maxillofacial Surgery},
volume = {34},
pages = {635--638},
address = {Department of Oral and Maxillofacial Surgery, General Hospital of Attica KAT, Athens, Greece. cmourouzis@ath.forthnet.gr},
abstract = {This study assessed the spectrum of maxillofacial fractures sustained during sports in Greece, discuss the aetiology in different sports and suggest protective measures. One hundred and twenty-five patients suffered facial fractures as a result of different sport activities. The factors evaluated were: type of sport involved, age, sex, mechanism of injury, site of fractures, associated non-maxillofacial injuries and mode of treatment. The ratio male to female was 9:1 and the highest incidence of sport-related facial fractures was found in the 21-30 year age group. Football was the most common sport-related to facial fractures and the main mechanism of injury was that of impact against another player's head. The most common were the mandibular fractures, followed by zygoma fractures. Furthermore, the angle of the mandible is the highest risk region for fracture. The majority of patients needed surgical treatment. Facial fractures during sports mainly affect the young and the majority of the patients are amateur athletes. Although these injuries are not usually severe, initial hospitalisation and surgical interventions may be required. Team sports are responsible for the majority of facial fractures.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Crisco, Joseph J; Chu, Jeffrey J; Greenwald, Richard M
An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers Journal Article
In: Journal of Biomechanical Engineering, vol. 126, pp. 849–854, 2004.
Abstract | BibTeX | Tags: Biomechanics
@article{Crisco2004,
title = {An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers},
author = {Crisco, Joseph J and Chu, Jeffrey J and Greenwald, Richard M},
year = {2004},
date = {2004-01-01},
journal = {Journal of Biomechanical Engineering},
volume = {126},
pages = {849--854},
address = {Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA. joseph_crisco@brown.edu},
abstract = {Accelerations of the head are the likely cause of concussion injury, but identifying the specific etiology of concussion has been difficult due to the lack of a valid animal or computer model. Contact sports, in which concussions are a rising health care concern, offer a unique research laboratory environment. However, measuring head acceleration in the field has many challenges including the need for large population sampling because of the relatively low incidence of concussions. We report a novel approach for calculating linear acceleration that can be incorporated into a head-mounted system for on-field use during contact sports. The advantages of this approach include the use of single-axis linear accelerometers, which reduce costs, and a nonorthogonal arrangement of the accelerometers, which simplifies the design criteria for a head-mounted and helmet compatible system. The purpose of this study was to describe the algorithm and evaluate its accuracy for measuring linear acceleration magnitude and impact location using computer simulation and experimental tests with various accelerometer configurations. A 10% error in magnitude and a 10 deg error in impact location were achieved using as few as six single-axis accelerometers mounted on a hemispherical headform.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Webbe, Frank M; Barth, Jeffrey T
Short-term and long-term outcome of athletic closed head injuries Journal Article
In: Clinics in Sports Medicine, vol. 22, pp. 577–592, 2003.
Abstract | BibTeX | Tags: Biomechanics
@article{Webbe2003a,
title = {Short-term and long-term outcome of athletic closed head injuries},
author = {Webbe, Frank M and Barth, Jeffrey T},
year = {2003},
date = {2003-01-01},
journal = {Clinics in Sports Medicine},
volume = {22},
pages = {577--592},
address = {School of Psychology, Florida Institute of Technology, Melbourne, FL 32901, USA.},
abstract = {The continued development of the sport environment as a laboratory for clinical investigation of mild head injury has greatly advanced the use of neuropsychological assessment in evaluating brain-injured athletes, and tracking their symptoms and recovery in an objective manner. The use of neurocognitive baseline measures has become critical in determining whether a brain-injured athlete has recovered function sufficiently to return to play. The rapid growth of computerized and web-based neurocognitive assessment measures provides an efficient, valid technology to put such testing within the reach of most institutions and organizations that field sport teams. Moreover, the knowledge of the recovery curve following mild head injury in the sport environment can be generalized to the management of MTBI in general clinical environments where baseline measures are unlikely. What we know today is that sideline assessments of severity are not predictive of which athletes will show the most typical 5- to 10-day recovery period and which will report persistent PCS complaints and exhibit impaired neurocognitive performance for an extended time. The research on mechanisms of brain injury in MTBI suggests that unpredictable, diffuse white-matter damage may control much of the variability in functional impairments and recovery duration. [References: 82]},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Vaccaro, Alexander R; Klein, Gregg R; Ciccoti, Michael; Pfaff, William L; Moulton, Mark J R; Hilibrand, Alan J; Watkins, Bob
Return to play criteria for the athlete with cervical spine injuries resulting in stinger and transient quadriplegia/paresis Journal Article
In: Spine Journal, vol. 2, pp. 351–356, 2002.
Abstract | BibTeX | Tags: Biomechanics
@article{Vaccaro2002,
title = {Return to play criteria for the athlete with cervical spine injuries resulting in stinger and transient quadriplegia/paresis},
author = {Vaccaro, Alexander R and Klein, Gregg R and Ciccoti, Michael and Pfaff, William L and Moulton, Mark J R and Hilibrand, Alan J and Watkins, Bob},
year = {2002},
date = {2002-01-01},
journal = {Spine Journal},
volume = {2},
pages = {351--356},
address = {Department of Orthopaedic Surgery, Thomas Jefferson University and the Rothman Institute, 925 Chestnut Street, 5th Floor, Philadelphia, PA 19107, USA. vaccaro3@yahoo.com},
abstract = {BACKGROUND CONTEXT: Fortunately, catastrophic cervical spinal cord injuries are relatively uncommon during athletic participation. Stinger and transient quadriplegia/paresis are more frequent injuries that have a wide spectrum of clinical severity and disabilities. Although the diagnosis of these injuries may not be clinically difficult, the treatment and decision about when or if the athlete may return to play after such an injury is often unclear. PURPOSE: This article reviews the current literature to help determine reasonable guidelines for return-to-play criteria after cervical spine injuries in the athlete. METHODS: The contemporary English literature and experience-based guidelines for return to play after cervical spine injuries in the athlete were reviewed. RESULTS: Despite the frequency of cervical-related injuries among athletes participating in contact and collision sports, no consensus exists within the medical field as to a standard guideline approach for return to preinjury activity level. CONCLUSION: The issue of return to play for an athlete after a cervical spine injury is controversial. Tremendous extrinsic pressures may be exerted on the physician from noninvolved and involved parties. The decision to return an athlete to a particular sport should be based on the mechanism of injury, objective anatomical injury (as demonstrated by clinical examination and radiographic evaluation) and an athlete's recovery response. [References: 21]},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Ruan, J; Prasad, P
The effects of skull thickness variations on human head dynamic impact responses Journal Article
In: Stapp Car Crash Journal, vol. 45, pp. 395–414, 2001.
Abstract | BibTeX | Tags: Biomechanics
@article{Ruan2001,
title = {The effects of skull thickness variations on human head dynamic impact responses},
author = {Ruan, J and Prasad, P},
year = {2001},
date = {2001-01-01},
journal = {Stapp Car Crash Journal},
volume = {45},
pages = {395--414},
address = {Ford Motor Company.},
abstract = {Variations in human skull thickness affecting human head dynamic impact responses were studied by finite element modeling techniques, experimental measurements, and histology examinations. The aims of the study were to better understand the influences of skull thickness variations on human head dynamic impact responses and the injury mechanisms of human head during direct impact. The thicknesses of the frontal bone of seven human cadaver skulls were measured using ultrasonic technology. These measurements were compared with previous experimental data. Histology of the skull was recorded and examined. The measured data were analyzed and then served as a reference to vary the skull thickness of a previously published three-dimensional finite element human head model to create four models with different skull thickness. The skull thicknesses modeled are 4.6 mm, 5.98 mm, 7.68 mm, and 9.61 mm. These models were impacted by a cylinder with a mass of 5.23 kg and an initial velocity of 6.33 m/s. Model responses were compared between models in terms of intracranial pressures, head impact accelerations, brain shear stresses, and skull von Mises stresses. It has been shown that the thickness of the skull influenced the dynamic responses of the head during direct impact. As skull thickness increased, skull deformation decreased as the skull absorbed less impact energy. However, this relationship cannot be linearly interpolated to the other parameters such as head acceleration and intracranial pressure responses. Based on model responses to half-sine wave pulses, skull and brain iso-stress curves were constructed for the thicker and thinner skulls. Thresholds for skull fracture and reversible concussion were established for the population represented by these skulls.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Sturmi, J E; Smith, C; Lombardo, J A
Mild brain trauma in sports. Diagnosis and treatment guidelines Journal Article
In: Sports Medicine, vol. 25, pp. 351–358, 1998.
Abstract | BibTeX | Tags: Biomechanics
@article{Sturmi1998,
title = {Mild brain trauma in sports. Diagnosis and treatment guidelines},
author = {Sturmi, J E and Smith, C and Lombardo, J A},
year = {1998},
date = {1998-01-01},
journal = {Sports Medicine},
volume = {25},
pages = {351--358},
address = {Ohio State University Athletic Department, Ohio State University, Columbus, USA.},
abstract = {Much has been written about the evaluation and management of mild brain trauma in sports. No less than 10 different 'guidelines' have been proposed and published to aid the clinician in the diagnosis of the condition. Too often, these guidelines have creating confusion instead of promoting an understanding of the spectrum of brain injury. As the understanding of the basic science of mild brain injury evolves, so must the approach to the concussed athlete. This article presents an up-to-date and clinically useful approach to the management of the athlete with a mild brain injury. The definition of 'concussion' is discussed and clarified and pertinent epidemiological data which highlight the importance of management skills as applied to athletes in a wide variety of sports are also reviewed. There is really no such thing as a 'mild concussion' if one considers the rare but catastrophic outcome of the second impact syndrome. For this reason, we review and expand upon the mechanisms of injury and pathophysiology. The accurate diagnosis of mild brain injury requires considerable experience, a high index of suspicion, a careful history and a series of examinations of the athlete, and a working knowledge of the athlete's personality and the likelihood of minimising their symptoms. The value of orientation questions pertinent to the athlete is now well established. Any focal neurological deficit or the deterioration of an athlete's condition warrants immediate hospitalisation, brain imaging and neurosurgical consultation. More commonly, athletes present with a brief alteration of consciousness, headache and amnesia and require careful examination and observation before returning to competition. The astute clinician will always err on the side of conservative management. The complete resolution of all symptoms before a return to play is imperative. Computerised tomography is very sensitive in the imaging of mild brain injuries. Neuropsychological testing is also very sensitive in the evaluation of brain injuries in athletes, and may become more clinically useful in the future. [References: 53]},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Hardy, W N; Khalil, T B; King, A I
Literature-review of head-injury biomechanics Journal Article
In: International Journal of Impact Engineering, vol. 15, pp. 561–586, 1994, ISSN: 0734-743X.
Abstract | Links | BibTeX | Tags: Biomechanics
@article{Hardy1994,
title = {Literature-review of head-injury biomechanics},
author = {Hardy, W N and Khalil, T B and King, A I},
doi = {10.1016/0734-743x(94)80034-7},
issn = {0734-743X},
year = {1994},
date = {1994-01-01},
journal = {International Journal of Impact Engineering},
volume = {15},
pages = {561--586},
abstract = {The high incidence of head injuries resulting from transportation system crashes, sports, military activities, falls, assaults, etc. contributes to a preponderance of head injury biomechanics research. A wealth of publications result, addressing phenomenological and mechanistic issues associated with head response to mechanical impact. This literature survey provides an assessment of hypothesized brain injury mechanisms, brain injury criteria, mathematical models of head injury and available techniques for measuring head kinematics and brain tissue deformations associated with exposure to dynamic loads.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Saunders, F W; Cledgett, P
Intracranial blood velocity in head-injury - A transcranial ultrasound doppler study Journal Article
In: Surgical Neurology, vol. 29, pp. 401–409, 1988, ISSN: 0090-3019.
BibTeX | Tags: Biomechanics
@article{Saunders1988,
title = {Intracranial blood velocity in head-injury - A transcranial ultrasound doppler study},
author = {Saunders, F W and Cledgett, P},
issn = {0090-3019},
year = {1988},
date = {1988-01-01},
journal = {Surgical Neurology},
volume = {29},
pages = {401--409},
address = {SAUNDERS, FW, QUEENS UNIV,DIV NEUROSURG,NONINVAS CEREBROVASC LAB,KINGSTON K7L 3N6,ONTARIO,CANADA.},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}
Parkinson, D
The biomechanics of concussion Journal Article
In: Clinical Neurosurgery, vol. 29, pp. 131–145, 1982.
BibTeX | Tags: Biomechanics
@article{Parkinson1982,
title = {The biomechanics of concussion},
author = {Parkinson, D},
year = {1982},
date = {1982-01-01},
journal = {Clinical Neurosurgery},
volume = {29},
pages = {131--145},
keywords = {Biomechanics},
pubstate = {published},
tppubtype = {article}
}