Richards, D; Ivarsson, B J; Scher, I; Hoover, R; Rodowicz, K; Cripton, P
Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts Journal Article
In: Sports Biomechanics, vol. 15, no. 4, pp. 385–396, 2016.
Abstract | BibTeX | Tags: *Craniocerebral Trauma/pc [Prevention & Control], *Head/ph [Physiology], *Hockey/ph [Physiology], *Protective Clothing, *Shoulder/ph [Physiology], Acceleration, Biomechanical Phenomena, Equipment Design, Humans, Male, Manikins, Materials testing, Reproducibility of Results, Risk Factors
@article{Richards2016,
title = {Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts},
author = {Richards, D and Ivarsson, B J and Scher, I and Hoover, R and Rodowicz, K and Cripton, P},
year = {2016},
date = {2016-01-01},
journal = {Sports Biomechanics},
volume = {15},
number = {4},
pages = {385--396},
abstract = {Ice hockey body checks involving direct shoulder-to-head contact frequently result in head injury. In the current study, we examined the effect of shoulder pad style on the likelihood of head injury from a shoulder-to-head check. Shoulder-to-head body checks were simulated by swinging a modified Hybrid-III anthropomorphic test device (ATD) with and without shoulder pads into a stationary Hybrid-III ATD at 21 km/h. Tests were conducted with three different styles of shoulder pads (traditional, integrated and tethered) and without shoulder pads for the purpose of control. Head response kinematics for the stationary ATD were measured. Compared to the case of no shoulder pads, the three different pad styles significantly (p \< 0.05) reduced peak resultant linear head accelerations of the stationary ATD by 35-56%. The integrated shoulder pads reduced linear head accelerations by an additional 18-21% beyond the other two styles of shoulder pads. The data presented here suggest that shoulder pads can be designed to help protect the head of the struck player in a shoulder-to-head check.},
keywords = {*Craniocerebral Trauma/pc [Prevention \& Control], *Head/ph [Physiology], *Hockey/ph [Physiology], *Protective Clothing, *Shoulder/ph [Physiology], Acceleration, Biomechanical Phenomena, Equipment Design, Humans, Male, Manikins, Materials testing, Reproducibility of Results, Risk Factors},
pubstate = {published},
tppubtype = {article}
}
Kawata, K; Rubin, L H; Lee, J H; Sim, T; Takahagi, M; Szwanki, V; Bellamy, A; Darvish, K; Assari, S; Henderer, J D; Tierney, R; Langford, D
Association of football subconcussive head impacts with ocular near point of convergence Journal Article
In: JAMA Ophthalmology, vol. 134, no. 7, pp. 763–769, 2016.
Abstract | Links | BibTeX | Tags: Acceleration, accelerometer, adult, Article, binocular convergence, Concussion, eye movement, follow up, football, head movement, human, KINEMATICS, major clinical study, Male, mouth protector, observational study, priority journal, prospective study, traumatic brain injury, Young Adult
@article{Kawata2016,
title = {Association of football subconcussive head impacts with ocular near point of convergence},
author = {Kawata, K and Rubin, L H and Lee, J H and Sim, T and Takahagi, M and Szwanki, V and Bellamy, A and Darvish, K and Assari, S and Henderer, J D and Tierney, R and Langford, D},
doi = {10.1001/jamaophthalmol.2016.1085},
year = {2016},
date = {2016-01-01},
journal = {JAMA Ophthalmology},
volume = {134},
number = {7},
pages = {763--769},
abstract = {IMPORTANCE An increased understanding of the relationship between subconcussive head impacts and near point of convergence (NPC) ocular-motor function may be useful in delineating traumatic brain injury. OBJECTIVE To investigate whether repetitive subconcussive head impacts during preseason football practice cause changes in NPC. DESIGN, SETTING, AND PARTICIPANTS This prospective, observational study of 29 National Collegiate Athletic Association Division I football players included baseline and preseason practices (1 noncontact and 4 contact), and postseason follow-up and outcome measures were obtained for each time. An accelerometer-embedded mouthguard measured head impact kinematics. Based on the sum of head impacts from all 5 practices, players were categorized into lower (n = 7) or higher (n = 22) impact groups. EXPOSURES Players participated in regular practices, and all head impacts greater than 10g from the 5 practices were recorded using the i1Biometerics Vector mouthguard (i1 Biometrics Inc). MAIN OUTCOMES AND MEASURES Near point of convergence measures and symptom scores. RESULTS A total of 1193 head impacts were recorded from 5 training camp practices in the 29 collegiate football players; 22 were categorized into the higher-impact group and 7 into the lower-impact group. Therewere significant differences in head impact kinematics between lower- and higher-impact groups (number of impacts, 6 vs 41 [lower impact minus higher impact = 35; 95%CI, 21-51; P \< .001]; linear acceleration, 99g vs 1112g [lower impact minus higher impact= 1013; 95%CI, 621 - 1578; P \< .001]; angular acceleration, 7589 radian/s2 vs 65016 radian/s2 [lower impact minus higher impact= 57 427; 95%CI , 31 123-80 498; P \< .001], respectively). The trajectory and cumulative burden of subconcussive impacts on NPC differed by group (F for group × linear trend1},
keywords = {Acceleration, accelerometer, adult, Article, binocular convergence, Concussion, eye movement, follow up, football, head movement, human, KINEMATICS, major clinical study, Male, mouth protector, observational study, priority journal, prospective study, traumatic brain injury, Young Adult},
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}
}
Lockhart, P A; Cronin, D S
Helmet liner evaluation to mitigate head response from primary blast exposure Journal Article
In: Computer Methods in Biomechanics & Biomedical Engineering, vol. 18, no. 6, pp. 635–645, 2015.
Abstract | BibTeX | Tags: *Blast Injuries/pc [Prevention & Control], *Craniocerebral Trauma/pc [Prevention & Control], *Explosions, *Head Protective Devices, Acceleration, Aluminum/ch [Chemistry], Biomechanical Phenomena, brain concussion, Brain Injuries, Brain/ph [Physiology], Computer simulation, CPD4NFA903 (Aluminum), Equipment Design, Head, Humans, intracranial pressure, Male, Materials testing
@article{Lockhart2015,
title = {Helmet liner evaluation to mitigate head response from primary blast exposure},
author = {Lockhart, P A and Cronin, D S},
year = {2015},
date = {2015-01-01},
journal = {Computer Methods in Biomechanics \& Biomedical Engineering},
volume = {18},
number = {6},
pages = {635--645},
abstract = {Head injury resulting from blast loading, including mild traumatic brain injury, has been identified as an important blast-related injury in modern conflict zones. A study was undertaken to investigate potential protective ballistic helmet liner materials to mitigate primary blast injury using a detailed sagittal plane head finite element model, developed and validated against previous studies of head kinematics resulting from blast exposure. Five measures reflecting the potential for brain injury that were investigated included intracranial pressure, brain tissue strain, head acceleration (linear and rotational) and the head injury criterion. In simulations, these measures provided consistent predictions for typical blast loading scenarios. Considering mitigation, various characteristics of foam material response were investigated and a factor analysis was performed which showed that the four most significant were the interaction effects between modulus and hysteretic response, stress-strain response, damping factor and density. Candidate materials were then identified using the predicted optimal material values. Polymeric foam was found to meet the density and modulus requirements; however, for all significant parameters, higher strength foams, such as aluminum foam, were found to provide the highest reduction in the potential for injury when compared against the unprotected head.},
keywords = {*Blast Injuries/pc [Prevention \& Control], *Craniocerebral Trauma/pc [Prevention \& Control], *Explosions, *Head Protective Devices, Acceleration, Aluminum/ch [Chemistry], Biomechanical Phenomena, brain concussion, Brain Injuries, Brain/ph [Physiology], Computer simulation, CPD4NFA903 (Aluminum), Equipment Design, Head, Humans, intracranial pressure, Male, Materials testing},
pubstate = {published},
tppubtype = {article}
}
Hernandez, F; Shull, P B; Camarillo, D B
Evaluation of a laboratory model of human head impact biomechanics Journal Article
In: Journal of Biomechanics, vol. 48, no. 12, pp. 3469–3477, 2015.
Abstract | BibTeX | Tags: *HEAD, *Laboratories, *Mechanical Phenomena, *Models, Acceleration, Biological, Biomechanical Phenomena, Brain Concussion/et [Etiology], Football/in [Injuries], Head Protective Devices, Humans, Male, Neck/ph [Physiology], Rotation, SAFETY
@article{Hernandez2015,
title = {Evaluation of a laboratory model of human head impact biomechanics},
author = {Hernandez, F and Shull, P B and Camarillo, D B},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanics},
volume = {48},
number = {12},
pages = {3469--3477},
abstract = {This work describes methodology for evaluating laboratory models of head impact biomechanics. Using this methodology, we investigated: how closely does twin-wire drop testing model head rotation in American football impacts? Head rotation is believed to cause mild traumatic brain injury (mTBI) but helmet safety standards only model head translations believed to cause severe TBI. It is unknown whether laboratory head impact models in safety standards, like twin-wire drop testing, reproduce six degree-of-freedom (6DOF) head impact biomechanics that may cause mTBI. We compared 6DOF measurements of 421 American football head impacts to twin-wire drop tests at impact sites and velocities weighted to represent typical field exposure. The highest rotational velocities produced by drop testing were the 74th percentile of non-injury field impacts. For a given translational acceleration level, drop testing underestimated field rotational acceleration by 46% and rotational velocity by 72%. Primary rotational acceleration frequencies were much larger in drop tests ($sim$100 Hz) than field impacts ($sim$10 Hz). Drop testing was physically unable to produce acceleration directions common in field impacts. Initial conditions of a single field impact were highly resolved in stereo high-speed video and reconstructed in a drop test. Reconstruction results reflected aggregate trends of lower amplitude rotational velocity and higher frequency rotational acceleration in drop testing, apparently due to twin-wire constraints and the absence of a neck. These results suggest twin-wire drop testing is limited in modeling head rotation during impact, and motivate continued evaluation of head impact models to ensure helmets are tested under conditions that may cause mTBI. Copyright © 2015 Elsevier Ltd. All rights reserved.},
keywords = {*HEAD, *Laboratories, *Mechanical Phenomena, *Models, Acceleration, Biological, Biomechanical Phenomena, Brain Concussion/et [Etiology], Football/in [Injuries], Head Protective Devices, Humans, Male, Neck/ph [Physiology], Rotation, SAFETY},
pubstate = {published},
tppubtype = {article}
}
Swartz, E E; Broglio, S P; Cook, S B; Cantu, R C; Ferrara, M S; Guskiewicz, K M; Myers, J L
Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players Journal Article
In: Journal of Athletic Training, vol. 50, no. 12, pp. 1219–1222, 2015.
Abstract | BibTeX | Tags: *Craniocerebral Trauma/pc [Prevention & Control], *Football/in [Injuries], *Physical Education and Training/mt [Methods], Acceleration, Head Protective Devices, Humans, Male, Prospective Studies, Universities
@article{Swartz2015,
title = {Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players},
author = {Swartz, E E and Broglio, S P and Cook, S B and Cantu, R C and Ferrara, M S and Guskiewicz, K M and Myers, J L},
year = {2015},
date = {2015-01-01},
journal = {Journal of Athletic Training},
volume = {50},
number = {12},
pages = {1219--1222},
abstract = {OBJECTIVE: To test a helmetless-tackling behavioral intervention for reducing head impacts in National Collegiate Athletic Association Division I football players. DESIGN: Randomized controlled clinical trial. SETTING: Football field. PATIENTS OR OTHER PARTICIPANTS: Fifty collegiate football players (intervention = 25},
keywords = {*Craniocerebral Trauma/pc [Prevention \& Control], *Football/in [Injuries], *Physical Education and Training/mt [Methods], Acceleration, Head Protective Devices, Humans, Male, Prospective Studies, Universities},
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}
}
Wang, H; Wang, B; Jackson, K; Miller, C M; Hasadsri, L; Llano, D; Rubin, R; Zimmerman, J; Johnson, C; Sutton, B
A novel head-neck cooling device for concussion injury in contact sports Journal Article
In: Translational Neuroscience, vol. 6, pp. 20–31, 2015.
Abstract | Links | BibTeX | Tags: Acceleration, Article, brain concussion, Brain hypothermia, brain perfusion, brain temperature, brain tissue, clinical study, cognition, contact sport, cooling, diving, exercise, exercise induced hyperthermia, experimental study, government, head neck cooling device, Head-neck cooling, human, hyperthermia, induced hypothermia, mild traumatic brain injury, nonhuman, priority journal, randomized controlled trial (topic), sport injury, Sports, surface property, thermal regulating system, thermal stimulation, thermoregulation, traumatic brain injury
@article{Wang2015a,
title = {A novel head-neck cooling device for concussion injury in contact sports},
author = {Wang, H and Wang, B and Jackson, K and Miller, C M and Hasadsri, L and Llano, D and Rubin, R and Zimmerman, J and Johnson, C and Sutton, B},
doi = {10.1515/tnsci-2015-0004},
year = {2015},
date = {2015-01-01},
journal = {Translational Neuroscience},
volume = {6},
pages = {20--31},
abstract = {Emerging research on the long-term impact of concussions on athletes has allowed public recognition of the potentially devastating effects of these and other mild head injuries. Mild traumatic brain injury (mTBI) is a multifaceted disease for which management remains a clinical challenge. Recent pre-clinical and clinical data strongly suggest a destructive synergism between brain temperature elevation and mTBI; conversely, brain hypothermia, with its broader, pleiotropic effects, represents the most potent neuro-protectant in laboratory studies to date. Although well-established in selected clinical conditions, a systemic approach to accomplish regional hypothermia has failed to yield an effective treatment strategy in traumatic brain injury (TBI). Furthermore, although systemic hypothermia remains a potentially valid treatment strategy for moderate to severe TBIs, it is neither practical nor safe for mTBIs. Therefore, selective head-neck cooling may represent an ideal strategy to provide therapeutic benefits to the brain. Optimizing brain temperature management using a National Aeronautics and Space Administration (NASA) spacesuit spinoff head-neck cooling technology before and/or after mTBI in contact sports may represent a sensible, practical, and effective method to potentially enhance recover and minimize post-injury deficits. In this paper, we discuss and summarize the anatomical, physiological, preclinical, and clinical data concerning NASA spinoff head-neck cooling technology as a potential treatment for mTBIs, particularly in the context of contact sports. © 2015 Huan Wang et al., licensee De Gruyter Open.},
keywords = {Acceleration, Article, brain concussion, Brain hypothermia, brain perfusion, brain temperature, brain tissue, clinical study, cognition, contact sport, cooling, diving, exercise, exercise induced hyperthermia, experimental study, government, head neck cooling device, Head-neck cooling, human, hyperthermia, induced hypothermia, mild traumatic brain injury, nonhuman, priority journal, randomized controlled trial (topic), sport injury, Sports, surface property, thermal regulating system, thermal stimulation, thermoregulation, traumatic brain injury},
pubstate = {published},
tppubtype = {article}
}
Caryn, R C; Hazell, T J; Dickey, J P
Transmission of acceleration from a synchronous vibration exercise platform to the head Journal Article
In: International Journal of Sports Medicine, vol. 35, no. 4, pp. 330–338, 2014.
Abstract | BibTeX | Tags: *Exercise/ph [Physiology], *HEAD, *Knee Joint/ph [Physiology], *Posture/ph [Physiology], *Sports Equipment, *Vibration, Acceleration, adult, Humans, Male
@article{Caryn2014,
title = {Transmission of acceleration from a synchronous vibration exercise platform to the head},
author = {Caryn, R C and Hazell, T J and Dickey, J P},
year = {2014},
date = {2014-01-01},
journal = {International Journal of Sports Medicine},
volume = {35},
number = {4},
pages = {330--338},
abstract = {Exercise vibration platforms are becoming commonplace in homes and fitness centers. However, excessive mechanical energy transferred to the head and eye can cause injury. The purpose of this study was to evaluate how changes in platform frequency and knee flexion angle affect acceleration transmission to the head. Participants (N=12) stood on a whole-body vibration platform with knee flexion angles of 0degree, 20degree, and 40degree to evaluate how changes in knee flexion affected head acceleration. 7 specific platform frequencies were tested between 20-50Hz at 2 peak-to-peak displacement settings (1 and 2mm nominal). Accelerations were measured with triaxial accelerometers at the platform and head to generate transmissibility ratios. Platform-to-head transmissibility was not significantly different between the 2 platform peak-to-peak amplitudes (P\>0.05). Transmissibility measures varied depending on platform frequency and knee angle (P\<0.05). Flexing the knees resulted in reduced head transmissibility at all frequencies (P\<0.05). Platform-to-head transmissibility values exceeded 1.0 at both 20 and 25Hz platform vibration frequencies with the knees in full extension. To reduce the risk of injury to structures of the head during vibration exercise, using platforms frequencies below 30Hz with small knee flexion angles (\<40degree) should be avoided. Copyright © Georg Thieme Verlag KG Stuttgart . New York.},
keywords = {*Exercise/ph [Physiology], *HEAD, *Knee Joint/ph [Physiology], *Posture/ph [Physiology], *Sports Equipment, *Vibration, Acceleration, adult, Humans, Male},
pubstate = {published},
tppubtype = {article}
}
Wu, L C; Zarnescu, L; Nangia, V; Cam, B; Camarillo, D B
A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard Journal Article
In: IEEE Transactions on Biomedical Engineering, vol. 61, no. 11, pp. 2659–2668, 2014.
Abstract | BibTeX | Tags: *Biomechanical Phenomena/ph [Physiology], *Head/ph [Physiology], *Monitoring, *Mouth Protectors, *Support Vector Machine, Acceleration, Accelerometry/is [Instrumentation], Ambulatory/is [Instrumentation], Ambulatory/mt [Methods], Closed, Computer-Assisted/is [Instrumen, football, Head Injuries, Humans, Infrared Rays, Monitoring, Reproducibility of Results, Sensitivity and Specificity, Signal Processing
@article{Wu2014,
title = {A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard},
author = {Wu, L C and Zarnescu, L and Nangia, V and Cam, B and Camarillo, D B},
year = {2014},
date = {2014-01-01},
journal = {IEEE Transactions on Biomedical Engineering},
volume = {61},
number = {11},
pages = {2659--2668},
abstract = {Injury from blunt head impacts causes acute neurological deficits and may lead to chronic neurodegeneration. A head impact detection device can serve both as a research tool for studying head injury mechanisms and a clinical tool for real-time trauma screening. The simplest approach is an acceleration thresholding algorithm, which may falsely detect high-acceleration spurious events such as manual manipulation of the device. We designed a head impact detection system that distinguishes head impacts from nonimpacts through two subsystems. First, we use infrared proximity sensing to determine if the mouthguard is worn on the teeth to filter out all off-teeth events. Second, on-teeth, nonimpact events are rejected using a support vector machine classifier trained on frequency domain features of linear acceleration and rotational velocity. The remaining events are classified as head impacts. In a controlled laboratory evaluation, the present system performed substantially better than a 10-g acceleration threshold in head impact detection (98% sensitivity, 99.99% specificity, 99% accuracy, and 99.98% precision, compared to 92% sensitivity, 58% specificity, 65% accuracy, and 37% precision). Once adapted for field deployment by training and validation with field data, this system has the potential to effectively detect head trauma in sports, military service, and other high-risk activities.},
keywords = {*Biomechanical Phenomena/ph [Physiology], *Head/ph [Physiology], *Monitoring, *Mouth Protectors, *Support Vector Machine, Acceleration, Accelerometry/is [Instrumentation], Ambulatory/is [Instrumentation], Ambulatory/mt [Methods], Closed, Computer-Assisted/is [Instrumen, football, Head Injuries, Humans, Infrared Rays, Monitoring, Reproducibility of Results, Sensitivity and Specificity, Signal Processing},
pubstate = {published},
tppubtype = {article}
}
McIntosh, A S; Lai, A; Schilter, E
Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests Journal Article
In: Traffic Injury Prevention, vol. 14, no. 5, pp. 501–508, 2013.
Abstract | BibTeX | Tags: *Accidents, *Bicycling/in [Injuries], *Craniocerebral Trauma/et [Etiology], *Head Protective Devices/ut [Utilization], Acceleration, Biological, Biomechanical Phenomena, Computer simulation, Humans, Male, Manikins, Models, Traffic/sn [Statistics & Numerical Dat
@article{McIntosh2013,
title = {Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests},
author = {McIntosh, A S and Lai, A and Schilter, E},
year = {2013},
date = {2013-01-01},
journal = {Traffic Injury Prevention},
volume = {14},
number = {5},
pages = {501--508},
abstract = {OBJECTIVE: To assess the factors, including helmet use, that contribute to head linear and angular acceleration in bicycle crash simulation tests. METHOD: A series of laboratory tests was undertaken using an oblique impact rig. The impact rig included a drop assembly with a Hybrid III head and neck. The head struck a horizontally moving striker plate. Head linear and angular acceleration and striker plate force were measured. The Head Injury Criterion was derived. The following test parameters were varied: drop height to a maximum of 1.5 m, horizontal speed to a maximum of 25 km/h, helmet/no helmet, impact orientation/location, and restraint adjustment. Additional radial impacts were conducted on the same helmet models for comparison purposes. Descriptive statistics were derived and multiple regression was applied to examine the role of each parameter. RESULTS: Helmet use was the most significant factor in reducing the magnitude of all outcome variables. Linear acceleration and the Head Injury Criterion were influenced by the drop height, whereas angular acceleration tended to be influenced by the horizontal speed and impact orientation/location. The restraint adjustment influenced the outcome variables, with lower coefficients of variation observed with the tight restraint. CONCLUSIONS: The study reinforces the benefits of wearing a bicycle helmet in a crash. The study also demonstrates that helmets do not increase angular head acceleration. The study assists in establishing the need for an agreed-upon international oblique helmet test as well as the boundary conditions for oblique helmet testing.},
keywords = {*Accidents, *Bicycling/in [Injuries], *Craniocerebral Trauma/et [Etiology], *Head Protective Devices/ut [Utilization], Acceleration, Biological, Biomechanical Phenomena, Computer simulation, Humans, Male, Manikins, Models, Traffic/sn [Statistics \& Numerical Dat},
pubstate = {published},
tppubtype = {article}
}
Ivancic, P C
Neck injury response to direct head impact Journal Article
In: Accident Analysis & Prevention, vol. 50, pp. 323–329, 2013.
Abstract | BibTeX | Tags: *Accidents, *Neck Injuries/et [Etiology], *Neck Injuries/pp [Physiopathology], Acceleration, ANALYSIS of variance, Biomechanical Phenomena, Cadaver, Humans, Manikins, Rotation, Traffic, VIDEO recording
@article{Ivancic2013,
title = {Neck injury response to direct head impact},
author = {Ivancic, P C},
year = {2013},
date = {2013-01-01},
journal = {Accident Analysis \& Prevention},
volume = {50},
pages = {323--329},
abstract = {Previous in vivo studies have observed flexion of the upper or upper/middle cervical spine and extension at inferior spinal levels due to direct head impacts. These studies hypothesized that hyperflexion may contribute to injury of the upper or middle cervical spine during real-life head impact. Our objectives were to determine the cervical spine injury response to direct head impact, document injuries, and compare our results with previously reported in vivo data. Our model consisted of a human cadaver neck (n=6) mounted to the torso of a rear impact dummy and carrying a surrogate head. Rearward force was applied to the model's forehead using a cable and pulley system and free-falling mass of 3.6kg followed by 16.7kg. High-speed digital cameras tracked head, vertebral, and pelvic motions. Average peak spinal rotations observed during impact were statistically compared (P\<0.05) to physiological ranges obtained from intact flexibility tests. Peak head impact force was 249 and 504N for the 3.6 and 16.7kg free-falling masses, respectively. Occipital condyle loads reached 205.3N posterior shear, 331.4N compression, and 7.4Nm extension moment. We observed significant increases in intervertebral extension peaks above physiologic at C6/7 (26.3degree vs. 5.7degree) and C7/T1 (29.7degree vs. 4.6degree) and macroscopic ligamentous and osseous injuries at C6 through T1 due to the 504N impacts. Our results indicate that a rearward head shear force causes complex neck loads of posterior shear, compression, and extension moment sufficient to injure the lower cervical spine. Real-life neck injuries due to motor vehicle crashes, sports impacts, or falls are likely due to combined loads transferred to the neck by direct head impact and torso inertial loads. Copyright © 2012 Elsevier Ltd. All rights reserved.},
keywords = {*Accidents, *Neck Injuries/et [Etiology], *Neck Injuries/pp [Physiopathology], Acceleration, ANALYSIS of variance, Biomechanical Phenomena, Cadaver, Humans, Manikins, Rotation, Traffic, VIDEO recording},
pubstate = {published},
tppubtype = {article}
}
McLeod, P; Reed, N; Gilson, S; Glennerster, A
How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality Journal Article
In: Vision Research, vol. 48, no. 13, pp. 1479–1487, 2008.
Abstract | BibTeX | Tags: *Head Movements/ph [Physiology], *Motion Perception/ph [Physiology], *Soccer/ph [Physiology], Acceleration, adult, Humans, Male, psychomotor performance, Reaction Time/ph [Physiology], User-Computer Interface
@article{McLeod2008,
title = {How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality},
author = {McLeod, P and Reed, N and Gilson, S and Glennerster, A},
year = {2008},
date = {2008-01-01},
journal = {Vision Research},
volume = {48},
number = {13},
pages = {1479--1487},
abstract = {We measured the movements of soccer players heading a football in a fully immersive virtual reality environment. In mid-flight the ball's trajectory was altered from its normal quasi-parabolic path to a linear one, producing a jump in the rate of change of the angle of elevation of gaze (alpha) from player to ball. One reaction time later the players adjusted their speed so that the rate of change of alpha increased when it had been reduced and reduced it when it had been increased. Since the result of the player's movement was to regain a value of the rate of change close to that before the disturbance, the data suggest that the players have an expectation of, and memory for, the pattern that the rate of change of alpha will follow during the flight. The results support the general claim that players intercepting balls use servo control strategies and are consistent with the particular claim of Optic Acceleration Cancellation theory that the servo strategy is to allow alpha to increase at a steadily decreasing rate.},
keywords = {*Head Movements/ph [Physiology], *Motion Perception/ph [Physiology], *Soccer/ph [Physiology], Acceleration, adult, Humans, Male, psychomotor performance, Reaction Time/ph [Physiology], User-Computer Interface},
pubstate = {published},
tppubtype = {article}
}
Hamberger, A; Huang, Y L; Zhu, H; Bao, F; Ding, M; Blennow, K; Olsson, A; Hansson, H A; Viano, D; Haglid, K G
Redistribution of neurofilaments and accumulation of beta-amyloid protein after brain injury by rotational acceleration of the head Journal Article
In: Journal of Neurotrauma, vol. 20, no. 2, pp. 169–178, 2003.
Abstract | BibTeX | Tags: *Amyloid beta-Peptides/me [Metabolism], *Brain Injuries/me [Metabolism], *Brain/me [Metabolism], *Neurofilament Proteins/me [Metabolism], 0 (Amyloid beta-Peptides), 0 (neurofilament protein L), 0 (Neurofilament Proteins), 108688-71-7 (neurofilament protein H), Acceleration, Animals, Brain Injuries/et [Etiology], immunohistochemistry, Phosphorylation, Rabbits, Rotation, Tissue Distribution
@article{Hamberger2003,
title = {Redistribution of neurofilaments and accumulation of beta-amyloid protein after brain injury by rotational acceleration of the head},
author = {Hamberger, A and Huang, Y L and Zhu, H and Bao, F and Ding, M and Blennow, K and Olsson, A and Hansson, H A and Viano, D and Haglid, K G},
year = {2003},
date = {2003-01-01},
journal = {Journal of Neurotrauma},
volume = {20},
number = {2},
pages = {169--178},
abstract = {Rotational acceleration of the head, as occurs in falls, car crashes, and sport injuries, may result in diffuse brain damage, with acute and chronic neurological and psychiatric symptoms. The present study addresses the effects of rotational trauma on the neuronal cytoskeleton, which stabilizes perikaryal, dendritic and axonal shape and function. The study focuses upon the distribution of (1) the phosphorylated form of the heavy neurofilament subunit, (2) the light neurofilament subunit, and (3) beta-amyloid, a marker for brain injury. While normally restricted to axons, the phosphorylated heavy neurofilament subunits were drastically decreased in the axons after rotational trauma. Instead, they accumulated in the neuronal perikarya, normally devoid of the phosphorylated subunit. This alteration was seen, not only in the cerebral cortex, but also in the hippocampus, the cervical spinal cord, the cerebellum, the cranial nerves and the pyramidal tract. The distribution of the light subunit of neurofilaments was also altered post trauma. Only a weak beta-amyloid immunoreactivity was detected in the brains of control animals. Promptly after the trauma, a large number of beta-amyloid positive neurons appeared. Intensely co-localized immunoreactivity for the light subunit of neurofilaments and of beta-amyloid was seen 3 days after the rotational trauma axons of in the subcortical white matter and in the granule cell layer of the dentate gyrus as well as in neurons of the hypoglossal nucleus. The reported alterations in the central nervous system neurons are similar to those in the human brain after closed head injury and in chronic degenerative diseases. Regions of importance for social behavior, memory and body movement were affected.},
keywords = {*Amyloid beta-Peptides/me [Metabolism], *Brain Injuries/me [Metabolism], *Brain/me [Metabolism], *Neurofilament Proteins/me [Metabolism], 0 (Amyloid beta-Peptides), 0 (neurofilament protein L), 0 (Neurofilament Proteins), 108688-71-7 (neurofilament protein H), Acceleration, Animals, Brain Injuries/et [Etiology], immunohistochemistry, Phosphorylation, Rabbits, Rotation, Tissue Distribution},
pubstate = {published},
tppubtype = {article}
}
McLean, A J
Brain injury without head impact? Journal Article
In: Journal of Neurotrauma, vol. 12, no. 4, pp. 621–625, 1995.
Abstract | BibTeX | Tags: *Brain Injuries/et [Etiology], Acceleration, Accidents, autopsy, Brain Injuries/mo [Mortality], cause of death, Head, Humans, Mechanical, Nonpenetrating, Stress, Traffic, Wounds
@article{McLean1995,
title = {Brain injury without head impact?},
author = {McLean, A J},
year = {1995},
date = {1995-01-01},
journal = {Journal of Neurotrauma},
volume = {12},
number = {4},
pages = {621--625},
abstract = {The proposition that acceleration of the brain without direct impact to the head can result in brain injury is examined by reviewing a series of 414 road users who were fatally injured in the vicinity of Adelaide, South Australia. The series comprises 170 pedestrians, 10 pedal cyclists, 143 motorcyclists, and 91 vehicle occupants. In each case a member of the research team attended the autopsy to look for evidence of impact on the body, particularly to the head or face. The brain was examined by a neuropathologist and the type and pattern of injury was recorded. The circumstances of the crash were investigated, including an examination of the crash site and the vehicles involved and, where relevant, interviews with witnesses. In cases involving a motorcyclist the helmet worn was retrieved by the police and assigned to the research unit for examination. Particular attention was paid to the identification of objects causing injury to the head or face and also to objects impacted by a helmet. Brain injury was recorded as a cause of death in 55% of the 403 cases for which there was a clear classification of cause of death. Brain injury, at any level of severity, was identified by a neuropathologist in 86 percent of the 414 fatally injured road users in the sample, including 24 cases that were examined microscopically. There were no cases in which there was an injury to the brain in the absence of evidence of an impact to the head.},
keywords = {*Brain Injuries/et [Etiology], Acceleration, Accidents, autopsy, Brain Injuries/mo [Mortality], cause of death, Head, Humans, Mechanical, Nonpenetrating, Stress, Traffic, Wounds},
pubstate = {published},
tppubtype = {article}
}
Richards, D; Ivarsson, B J; Scher, I; Hoover, R; Rodowicz, K; Cripton, P
Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts Journal Article
In: Sports Biomechanics, vol. 15, no. 4, pp. 385–396, 2016.
@article{Richards2016,
title = {Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts},
author = {Richards, D and Ivarsson, B J and Scher, I and Hoover, R and Rodowicz, K and Cripton, P},
year = {2016},
date = {2016-01-01},
journal = {Sports Biomechanics},
volume = {15},
number = {4},
pages = {385--396},
abstract = {Ice hockey body checks involving direct shoulder-to-head contact frequently result in head injury. In the current study, we examined the effect of shoulder pad style on the likelihood of head injury from a shoulder-to-head check. Shoulder-to-head body checks were simulated by swinging a modified Hybrid-III anthropomorphic test device (ATD) with and without shoulder pads into a stationary Hybrid-III ATD at 21 km/h. Tests were conducted with three different styles of shoulder pads (traditional, integrated and tethered) and without shoulder pads for the purpose of control. Head response kinematics for the stationary ATD were measured. Compared to the case of no shoulder pads, the three different pad styles significantly (p \< 0.05) reduced peak resultant linear head accelerations of the stationary ATD by 35-56%. The integrated shoulder pads reduced linear head accelerations by an additional 18-21% beyond the other two styles of shoulder pads. The data presented here suggest that shoulder pads can be designed to help protect the head of the struck player in a shoulder-to-head check.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kawata, K; Rubin, L H; Lee, J H; Sim, T; Takahagi, M; Szwanki, V; Bellamy, A; Darvish, K; Assari, S; Henderer, J D; Tierney, R; Langford, D
Association of football subconcussive head impacts with ocular near point of convergence Journal Article
In: JAMA Ophthalmology, vol. 134, no. 7, pp. 763–769, 2016.
@article{Kawata2016,
title = {Association of football subconcussive head impacts with ocular near point of convergence},
author = {Kawata, K and Rubin, L H and Lee, J H and Sim, T and Takahagi, M and Szwanki, V and Bellamy, A and Darvish, K and Assari, S and Henderer, J D and Tierney, R and Langford, D},
doi = {10.1001/jamaophthalmol.2016.1085},
year = {2016},
date = {2016-01-01},
journal = {JAMA Ophthalmology},
volume = {134},
number = {7},
pages = {763--769},
abstract = {IMPORTANCE An increased understanding of the relationship between subconcussive head impacts and near point of convergence (NPC) ocular-motor function may be useful in delineating traumatic brain injury. OBJECTIVE To investigate whether repetitive subconcussive head impacts during preseason football practice cause changes in NPC. DESIGN, SETTING, AND PARTICIPANTS This prospective, observational study of 29 National Collegiate Athletic Association Division I football players included baseline and preseason practices (1 noncontact and 4 contact), and postseason follow-up and outcome measures were obtained for each time. An accelerometer-embedded mouthguard measured head impact kinematics. Based on the sum of head impacts from all 5 practices, players were categorized into lower (n = 7) or higher (n = 22) impact groups. EXPOSURES Players participated in regular practices, and all head impacts greater than 10g from the 5 practices were recorded using the i1Biometerics Vector mouthguard (i1 Biometrics Inc). MAIN OUTCOMES AND MEASURES Near point of convergence measures and symptom scores. RESULTS A total of 1193 head impacts were recorded from 5 training camp practices in the 29 collegiate football players; 22 were categorized into the higher-impact group and 7 into the lower-impact group. Therewere significant differences in head impact kinematics between lower- and higher-impact groups (number of impacts, 6 vs 41 [lower impact minus higher impact = 35; 95%CI, 21-51; P \< .001]; linear acceleration, 99g vs 1112g [lower impact minus higher impact= 1013; 95%CI, 621 - 1578; P \< .001]; angular acceleration, 7589 radian/s2 vs 65016 radian/s2 [lower impact minus higher impact= 57 427; 95%CI , 31 123-80 498; P \< .001], respectively). The trajectory and cumulative burden of subconcussive impacts on NPC differed by group (F for group × linear trend1},
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}
}
Lockhart, P A; Cronin, D S
Helmet liner evaluation to mitigate head response from primary blast exposure Journal Article
In: Computer Methods in Biomechanics & Biomedical Engineering, vol. 18, no. 6, pp. 635–645, 2015.
@article{Lockhart2015,
title = {Helmet liner evaluation to mitigate head response from primary blast exposure},
author = {Lockhart, P A and Cronin, D S},
year = {2015},
date = {2015-01-01},
journal = {Computer Methods in Biomechanics \& Biomedical Engineering},
volume = {18},
number = {6},
pages = {635--645},
abstract = {Head injury resulting from blast loading, including mild traumatic brain injury, has been identified as an important blast-related injury in modern conflict zones. A study was undertaken to investigate potential protective ballistic helmet liner materials to mitigate primary blast injury using a detailed sagittal plane head finite element model, developed and validated against previous studies of head kinematics resulting from blast exposure. Five measures reflecting the potential for brain injury that were investigated included intracranial pressure, brain tissue strain, head acceleration (linear and rotational) and the head injury criterion. In simulations, these measures provided consistent predictions for typical blast loading scenarios. Considering mitigation, various characteristics of foam material response were investigated and a factor analysis was performed which showed that the four most significant were the interaction effects between modulus and hysteretic response, stress-strain response, damping factor and density. Candidate materials were then identified using the predicted optimal material values. Polymeric foam was found to meet the density and modulus requirements; however, for all significant parameters, higher strength foams, such as aluminum foam, were found to provide the highest reduction in the potential for injury when compared against the unprotected head.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hernandez, F; Shull, P B; Camarillo, D B
Evaluation of a laboratory model of human head impact biomechanics Journal Article
In: Journal of Biomechanics, vol. 48, no. 12, pp. 3469–3477, 2015.
@article{Hernandez2015,
title = {Evaluation of a laboratory model of human head impact biomechanics},
author = {Hernandez, F and Shull, P B and Camarillo, D B},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanics},
volume = {48},
number = {12},
pages = {3469--3477},
abstract = {This work describes methodology for evaluating laboratory models of head impact biomechanics. Using this methodology, we investigated: how closely does twin-wire drop testing model head rotation in American football impacts? Head rotation is believed to cause mild traumatic brain injury (mTBI) but helmet safety standards only model head translations believed to cause severe TBI. It is unknown whether laboratory head impact models in safety standards, like twin-wire drop testing, reproduce six degree-of-freedom (6DOF) head impact biomechanics that may cause mTBI. We compared 6DOF measurements of 421 American football head impacts to twin-wire drop tests at impact sites and velocities weighted to represent typical field exposure. The highest rotational velocities produced by drop testing were the 74th percentile of non-injury field impacts. For a given translational acceleration level, drop testing underestimated field rotational acceleration by 46% and rotational velocity by 72%. Primary rotational acceleration frequencies were much larger in drop tests ($sim$100 Hz) than field impacts ($sim$10 Hz). Drop testing was physically unable to produce acceleration directions common in field impacts. Initial conditions of a single field impact were highly resolved in stereo high-speed video and reconstructed in a drop test. Reconstruction results reflected aggregate trends of lower amplitude rotational velocity and higher frequency rotational acceleration in drop testing, apparently due to twin-wire constraints and the absence of a neck. These results suggest twin-wire drop testing is limited in modeling head rotation during impact, and motivate continued evaluation of head impact models to ensure helmets are tested under conditions that may cause mTBI. Copyright © 2015 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Swartz, E E; Broglio, S P; Cook, S B; Cantu, R C; Ferrara, M S; Guskiewicz, K M; Myers, J L
Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players Journal Article
In: Journal of Athletic Training, vol. 50, no. 12, pp. 1219–1222, 2015.
@article{Swartz2015,
title = {Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players},
author = {Swartz, E E and Broglio, S P and Cook, S B and Cantu, R C and Ferrara, M S and Guskiewicz, K M and Myers, J L},
year = {2015},
date = {2015-01-01},
journal = {Journal of Athletic Training},
volume = {50},
number = {12},
pages = {1219--1222},
abstract = {OBJECTIVE: To test a helmetless-tackling behavioral intervention for reducing head impacts in National Collegiate Athletic Association Division I football players. DESIGN: Randomized controlled clinical trial. SETTING: Football field. PATIENTS OR OTHER PARTICIPANTS: Fifty collegiate football players (intervention = 25},
keywords = {},
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.
@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 = {},
pubstate = {published},
tppubtype = {article}
}
Wang, H; Wang, B; Jackson, K; Miller, C M; Hasadsri, L; Llano, D; Rubin, R; Zimmerman, J; Johnson, C; Sutton, B
A novel head-neck cooling device for concussion injury in contact sports Journal Article
In: Translational Neuroscience, vol. 6, pp. 20–31, 2015.
@article{Wang2015a,
title = {A novel head-neck cooling device for concussion injury in contact sports},
author = {Wang, H and Wang, B and Jackson, K and Miller, C M and Hasadsri, L and Llano, D and Rubin, R and Zimmerman, J and Johnson, C and Sutton, B},
doi = {10.1515/tnsci-2015-0004},
year = {2015},
date = {2015-01-01},
journal = {Translational Neuroscience},
volume = {6},
pages = {20--31},
abstract = {Emerging research on the long-term impact of concussions on athletes has allowed public recognition of the potentially devastating effects of these and other mild head injuries. Mild traumatic brain injury (mTBI) is a multifaceted disease for which management remains a clinical challenge. Recent pre-clinical and clinical data strongly suggest a destructive synergism between brain temperature elevation and mTBI; conversely, brain hypothermia, with its broader, pleiotropic effects, represents the most potent neuro-protectant in laboratory studies to date. Although well-established in selected clinical conditions, a systemic approach to accomplish regional hypothermia has failed to yield an effective treatment strategy in traumatic brain injury (TBI). Furthermore, although systemic hypothermia remains a potentially valid treatment strategy for moderate to severe TBIs, it is neither practical nor safe for mTBIs. Therefore, selective head-neck cooling may represent an ideal strategy to provide therapeutic benefits to the brain. Optimizing brain temperature management using a National Aeronautics and Space Administration (NASA) spacesuit spinoff head-neck cooling technology before and/or after mTBI in contact sports may represent a sensible, practical, and effective method to potentially enhance recover and minimize post-injury deficits. In this paper, we discuss and summarize the anatomical, physiological, preclinical, and clinical data concerning NASA spinoff head-neck cooling technology as a potential treatment for mTBIs, particularly in the context of contact sports. © 2015 Huan Wang et al., licensee De Gruyter Open.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Caryn, R C; Hazell, T J; Dickey, J P
Transmission of acceleration from a synchronous vibration exercise platform to the head Journal Article
In: International Journal of Sports Medicine, vol. 35, no. 4, pp. 330–338, 2014.
@article{Caryn2014,
title = {Transmission of acceleration from a synchronous vibration exercise platform to the head},
author = {Caryn, R C and Hazell, T J and Dickey, J P},
year = {2014},
date = {2014-01-01},
journal = {International Journal of Sports Medicine},
volume = {35},
number = {4},
pages = {330--338},
abstract = {Exercise vibration platforms are becoming commonplace in homes and fitness centers. However, excessive mechanical energy transferred to the head and eye can cause injury. The purpose of this study was to evaluate how changes in platform frequency and knee flexion angle affect acceleration transmission to the head. Participants (N=12) stood on a whole-body vibration platform with knee flexion angles of 0degree, 20degree, and 40degree to evaluate how changes in knee flexion affected head acceleration. 7 specific platform frequencies were tested between 20-50Hz at 2 peak-to-peak displacement settings (1 and 2mm nominal). Accelerations were measured with triaxial accelerometers at the platform and head to generate transmissibility ratios. Platform-to-head transmissibility was not significantly different between the 2 platform peak-to-peak amplitudes (P\>0.05). Transmissibility measures varied depending on platform frequency and knee angle (P\<0.05). Flexing the knees resulted in reduced head transmissibility at all frequencies (P\<0.05). Platform-to-head transmissibility values exceeded 1.0 at both 20 and 25Hz platform vibration frequencies with the knees in full extension. To reduce the risk of injury to structures of the head during vibration exercise, using platforms frequencies below 30Hz with small knee flexion angles (\<40degree) should be avoided. Copyright © Georg Thieme Verlag KG Stuttgart . New York.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Wu, L C; Zarnescu, L; Nangia, V; Cam, B; Camarillo, D B
A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard Journal Article
In: IEEE Transactions on Biomedical Engineering, vol. 61, no. 11, pp. 2659–2668, 2014.
@article{Wu2014,
title = {A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard},
author = {Wu, L C and Zarnescu, L and Nangia, V and Cam, B and Camarillo, D B},
year = {2014},
date = {2014-01-01},
journal = {IEEE Transactions on Biomedical Engineering},
volume = {61},
number = {11},
pages = {2659--2668},
abstract = {Injury from blunt head impacts causes acute neurological deficits and may lead to chronic neurodegeneration. A head impact detection device can serve both as a research tool for studying head injury mechanisms and a clinical tool for real-time trauma screening. The simplest approach is an acceleration thresholding algorithm, which may falsely detect high-acceleration spurious events such as manual manipulation of the device. We designed a head impact detection system that distinguishes head impacts from nonimpacts through two subsystems. First, we use infrared proximity sensing to determine if the mouthguard is worn on the teeth to filter out all off-teeth events. Second, on-teeth, nonimpact events are rejected using a support vector machine classifier trained on frequency domain features of linear acceleration and rotational velocity. The remaining events are classified as head impacts. In a controlled laboratory evaluation, the present system performed substantially better than a 10-g acceleration threshold in head impact detection (98% sensitivity, 99.99% specificity, 99% accuracy, and 99.98% precision, compared to 92% sensitivity, 58% specificity, 65% accuracy, and 37% precision). Once adapted for field deployment by training and validation with field data, this system has the potential to effectively detect head trauma in sports, military service, and other high-risk activities.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
McIntosh, A S; Lai, A; Schilter, E
Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests Journal Article
In: Traffic Injury Prevention, vol. 14, no. 5, pp. 501–508, 2013.
@article{McIntosh2013,
title = {Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests},
author = {McIntosh, A S and Lai, A and Schilter, E},
year = {2013},
date = {2013-01-01},
journal = {Traffic Injury Prevention},
volume = {14},
number = {5},
pages = {501--508},
abstract = {OBJECTIVE: To assess the factors, including helmet use, that contribute to head linear and angular acceleration in bicycle crash simulation tests. METHOD: A series of laboratory tests was undertaken using an oblique impact rig. The impact rig included a drop assembly with a Hybrid III head and neck. The head struck a horizontally moving striker plate. Head linear and angular acceleration and striker plate force were measured. The Head Injury Criterion was derived. The following test parameters were varied: drop height to a maximum of 1.5 m, horizontal speed to a maximum of 25 km/h, helmet/no helmet, impact orientation/location, and restraint adjustment. Additional radial impacts were conducted on the same helmet models for comparison purposes. Descriptive statistics were derived and multiple regression was applied to examine the role of each parameter. RESULTS: Helmet use was the most significant factor in reducing the magnitude of all outcome variables. Linear acceleration and the Head Injury Criterion were influenced by the drop height, whereas angular acceleration tended to be influenced by the horizontal speed and impact orientation/location. The restraint adjustment influenced the outcome variables, with lower coefficients of variation observed with the tight restraint. CONCLUSIONS: The study reinforces the benefits of wearing a bicycle helmet in a crash. The study also demonstrates that helmets do not increase angular head acceleration. The study assists in establishing the need for an agreed-upon international oblique helmet test as well as the boundary conditions for oblique helmet testing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ivancic, P C
Neck injury response to direct head impact Journal Article
In: Accident Analysis & Prevention, vol. 50, pp. 323–329, 2013.
@article{Ivancic2013,
title = {Neck injury response to direct head impact},
author = {Ivancic, P C},
year = {2013},
date = {2013-01-01},
journal = {Accident Analysis \& Prevention},
volume = {50},
pages = {323--329},
abstract = {Previous in vivo studies have observed flexion of the upper or upper/middle cervical spine and extension at inferior spinal levels due to direct head impacts. These studies hypothesized that hyperflexion may contribute to injury of the upper or middle cervical spine during real-life head impact. Our objectives were to determine the cervical spine injury response to direct head impact, document injuries, and compare our results with previously reported in vivo data. Our model consisted of a human cadaver neck (n=6) mounted to the torso of a rear impact dummy and carrying a surrogate head. Rearward force was applied to the model's forehead using a cable and pulley system and free-falling mass of 3.6kg followed by 16.7kg. High-speed digital cameras tracked head, vertebral, and pelvic motions. Average peak spinal rotations observed during impact were statistically compared (P\<0.05) to physiological ranges obtained from intact flexibility tests. Peak head impact force was 249 and 504N for the 3.6 and 16.7kg free-falling masses, respectively. Occipital condyle loads reached 205.3N posterior shear, 331.4N compression, and 7.4Nm extension moment. We observed significant increases in intervertebral extension peaks above physiologic at C6/7 (26.3degree vs. 5.7degree) and C7/T1 (29.7degree vs. 4.6degree) and macroscopic ligamentous and osseous injuries at C6 through T1 due to the 504N impacts. Our results indicate that a rearward head shear force causes complex neck loads of posterior shear, compression, and extension moment sufficient to injure the lower cervical spine. Real-life neck injuries due to motor vehicle crashes, sports impacts, or falls are likely due to combined loads transferred to the neck by direct head impact and torso inertial loads. Copyright © 2012 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
McLeod, P; Reed, N; Gilson, S; Glennerster, A
How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality Journal Article
In: Vision Research, vol. 48, no. 13, pp. 1479–1487, 2008.
@article{McLeod2008,
title = {How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality},
author = {McLeod, P and Reed, N and Gilson, S and Glennerster, A},
year = {2008},
date = {2008-01-01},
journal = {Vision Research},
volume = {48},
number = {13},
pages = {1479--1487},
abstract = {We measured the movements of soccer players heading a football in a fully immersive virtual reality environment. In mid-flight the ball's trajectory was altered from its normal quasi-parabolic path to a linear one, producing a jump in the rate of change of the angle of elevation of gaze (alpha) from player to ball. One reaction time later the players adjusted their speed so that the rate of change of alpha increased when it had been reduced and reduced it when it had been increased. Since the result of the player's movement was to regain a value of the rate of change close to that before the disturbance, the data suggest that the players have an expectation of, and memory for, the pattern that the rate of change of alpha will follow during the flight. The results support the general claim that players intercepting balls use servo control strategies and are consistent with the particular claim of Optic Acceleration Cancellation theory that the servo strategy is to allow alpha to increase at a steadily decreasing rate.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hamberger, A; Huang, Y L; Zhu, H; Bao, F; Ding, M; Blennow, K; Olsson, A; Hansson, H A; Viano, D; Haglid, K G
Redistribution of neurofilaments and accumulation of beta-amyloid protein after brain injury by rotational acceleration of the head Journal Article
In: Journal of Neurotrauma, vol. 20, no. 2, pp. 169–178, 2003.
@article{Hamberger2003,
title = {Redistribution of neurofilaments and accumulation of beta-amyloid protein after brain injury by rotational acceleration of the head},
author = {Hamberger, A and Huang, Y L and Zhu, H and Bao, F and Ding, M and Blennow, K and Olsson, A and Hansson, H A and Viano, D and Haglid, K G},
year = {2003},
date = {2003-01-01},
journal = {Journal of Neurotrauma},
volume = {20},
number = {2},
pages = {169--178},
abstract = {Rotational acceleration of the head, as occurs in falls, car crashes, and sport injuries, may result in diffuse brain damage, with acute and chronic neurological and psychiatric symptoms. The present study addresses the effects of rotational trauma on the neuronal cytoskeleton, which stabilizes perikaryal, dendritic and axonal shape and function. The study focuses upon the distribution of (1) the phosphorylated form of the heavy neurofilament subunit, (2) the light neurofilament subunit, and (3) beta-amyloid, a marker for brain injury. While normally restricted to axons, the phosphorylated heavy neurofilament subunits were drastically decreased in the axons after rotational trauma. Instead, they accumulated in the neuronal perikarya, normally devoid of the phosphorylated subunit. This alteration was seen, not only in the cerebral cortex, but also in the hippocampus, the cervical spinal cord, the cerebellum, the cranial nerves and the pyramidal tract. The distribution of the light subunit of neurofilaments was also altered post trauma. Only a weak beta-amyloid immunoreactivity was detected in the brains of control animals. Promptly after the trauma, a large number of beta-amyloid positive neurons appeared. Intensely co-localized immunoreactivity for the light subunit of neurofilaments and of beta-amyloid was seen 3 days after the rotational trauma axons of in the subcortical white matter and in the granule cell layer of the dentate gyrus as well as in neurons of the hypoglossal nucleus. The reported alterations in the central nervous system neurons are similar to those in the human brain after closed head injury and in chronic degenerative diseases. Regions of importance for social behavior, memory and body movement were affected.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
McLean, A J
Brain injury without head impact? Journal Article
In: Journal of Neurotrauma, vol. 12, no. 4, pp. 621–625, 1995.
@article{McLean1995,
title = {Brain injury without head impact?},
author = {McLean, A J},
year = {1995},
date = {1995-01-01},
journal = {Journal of Neurotrauma},
volume = {12},
number = {4},
pages = {621--625},
abstract = {The proposition that acceleration of the brain without direct impact to the head can result in brain injury is examined by reviewing a series of 414 road users who were fatally injured in the vicinity of Adelaide, South Australia. The series comprises 170 pedestrians, 10 pedal cyclists, 143 motorcyclists, and 91 vehicle occupants. In each case a member of the research team attended the autopsy to look for evidence of impact on the body, particularly to the head or face. The brain was examined by a neuropathologist and the type and pattern of injury was recorded. The circumstances of the crash were investigated, including an examination of the crash site and the vehicles involved and, where relevant, interviews with witnesses. In cases involving a motorcyclist the helmet worn was retrieved by the police and assigned to the research unit for examination. Particular attention was paid to the identification of objects causing injury to the head or face and also to objects impacted by a helmet. Brain injury was recorded as a cause of death in 55% of the 403 cases for which there was a clear classification of cause of death. Brain injury, at any level of severity, was identified by a neuropathologist in 86 percent of the 414 fatally injured road users in the sample, including 24 cases that were examined microscopically. There were no cases in which there was an injury to the brain in the absence of evidence of an impact to the head.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Richards, D; Ivarsson, B J; Scher, I; Hoover, R; Rodowicz, K; Cripton, P
Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts Journal Article
In: Sports Biomechanics, vol. 15, no. 4, pp. 385–396, 2016.
Abstract | BibTeX | Tags: *Craniocerebral Trauma/pc [Prevention & Control], *Head/ph [Physiology], *Hockey/ph [Physiology], *Protective Clothing, *Shoulder/ph [Physiology], Acceleration, Biomechanical Phenomena, Equipment Design, Humans, Male, Manikins, Materials testing, Reproducibility of Results, Risk Factors
@article{Richards2016,
title = {Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts},
author = {Richards, D and Ivarsson, B J and Scher, I and Hoover, R and Rodowicz, K and Cripton, P},
year = {2016},
date = {2016-01-01},
journal = {Sports Biomechanics},
volume = {15},
number = {4},
pages = {385--396},
abstract = {Ice hockey body checks involving direct shoulder-to-head contact frequently result in head injury. In the current study, we examined the effect of shoulder pad style on the likelihood of head injury from a shoulder-to-head check. Shoulder-to-head body checks were simulated by swinging a modified Hybrid-III anthropomorphic test device (ATD) with and without shoulder pads into a stationary Hybrid-III ATD at 21 km/h. Tests were conducted with three different styles of shoulder pads (traditional, integrated and tethered) and without shoulder pads for the purpose of control. Head response kinematics for the stationary ATD were measured. Compared to the case of no shoulder pads, the three different pad styles significantly (p \< 0.05) reduced peak resultant linear head accelerations of the stationary ATD by 35-56%. The integrated shoulder pads reduced linear head accelerations by an additional 18-21% beyond the other two styles of shoulder pads. The data presented here suggest that shoulder pads can be designed to help protect the head of the struck player in a shoulder-to-head check.},
keywords = {*Craniocerebral Trauma/pc [Prevention \& Control], *Head/ph [Physiology], *Hockey/ph [Physiology], *Protective Clothing, *Shoulder/ph [Physiology], Acceleration, Biomechanical Phenomena, Equipment Design, Humans, Male, Manikins, Materials testing, Reproducibility of Results, Risk Factors},
pubstate = {published},
tppubtype = {article}
}
Kawata, K; Rubin, L H; Lee, J H; Sim, T; Takahagi, M; Szwanki, V; Bellamy, A; Darvish, K; Assari, S; Henderer, J D; Tierney, R; Langford, D
Association of football subconcussive head impacts with ocular near point of convergence Journal Article
In: JAMA Ophthalmology, vol. 134, no. 7, pp. 763–769, 2016.
Abstract | Links | BibTeX | Tags: Acceleration, accelerometer, adult, Article, binocular convergence, Concussion, eye movement, follow up, football, head movement, human, KINEMATICS, major clinical study, Male, mouth protector, observational study, priority journal, prospective study, traumatic brain injury, Young Adult
@article{Kawata2016,
title = {Association of football subconcussive head impacts with ocular near point of convergence},
author = {Kawata, K and Rubin, L H and Lee, J H and Sim, T and Takahagi, M and Szwanki, V and Bellamy, A and Darvish, K and Assari, S and Henderer, J D and Tierney, R and Langford, D},
doi = {10.1001/jamaophthalmol.2016.1085},
year = {2016},
date = {2016-01-01},
journal = {JAMA Ophthalmology},
volume = {134},
number = {7},
pages = {763--769},
abstract = {IMPORTANCE An increased understanding of the relationship between subconcussive head impacts and near point of convergence (NPC) ocular-motor function may be useful in delineating traumatic brain injury. OBJECTIVE To investigate whether repetitive subconcussive head impacts during preseason football practice cause changes in NPC. DESIGN, SETTING, AND PARTICIPANTS This prospective, observational study of 29 National Collegiate Athletic Association Division I football players included baseline and preseason practices (1 noncontact and 4 contact), and postseason follow-up and outcome measures were obtained for each time. An accelerometer-embedded mouthguard measured head impact kinematics. Based on the sum of head impacts from all 5 practices, players were categorized into lower (n = 7) or higher (n = 22) impact groups. EXPOSURES Players participated in regular practices, and all head impacts greater than 10g from the 5 practices were recorded using the i1Biometerics Vector mouthguard (i1 Biometrics Inc). MAIN OUTCOMES AND MEASURES Near point of convergence measures and symptom scores. RESULTS A total of 1193 head impacts were recorded from 5 training camp practices in the 29 collegiate football players; 22 were categorized into the higher-impact group and 7 into the lower-impact group. Therewere significant differences in head impact kinematics between lower- and higher-impact groups (number of impacts, 6 vs 41 [lower impact minus higher impact = 35; 95%CI, 21-51; P \< .001]; linear acceleration, 99g vs 1112g [lower impact minus higher impact= 1013; 95%CI, 621 - 1578; P \< .001]; angular acceleration, 7589 radian/s2 vs 65016 radian/s2 [lower impact minus higher impact= 57 427; 95%CI , 31 123-80 498; P \< .001], respectively). The trajectory and cumulative burden of subconcussive impacts on NPC differed by group (F for group × linear trend1},
keywords = {Acceleration, accelerometer, adult, Article, binocular convergence, Concussion, eye movement, follow up, football, head movement, human, KINEMATICS, major clinical study, Male, mouth protector, observational study, priority journal, prospective study, traumatic brain injury, Young Adult},
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}
}
Lockhart, P A; Cronin, D S
Helmet liner evaluation to mitigate head response from primary blast exposure Journal Article
In: Computer Methods in Biomechanics & Biomedical Engineering, vol. 18, no. 6, pp. 635–645, 2015.
Abstract | BibTeX | Tags: *Blast Injuries/pc [Prevention & Control], *Craniocerebral Trauma/pc [Prevention & Control], *Explosions, *Head Protective Devices, Acceleration, Aluminum/ch [Chemistry], Biomechanical Phenomena, brain concussion, Brain Injuries, Brain/ph [Physiology], Computer simulation, CPD4NFA903 (Aluminum), Equipment Design, Head, Humans, intracranial pressure, Male, Materials testing
@article{Lockhart2015,
title = {Helmet liner evaluation to mitigate head response from primary blast exposure},
author = {Lockhart, P A and Cronin, D S},
year = {2015},
date = {2015-01-01},
journal = {Computer Methods in Biomechanics \& Biomedical Engineering},
volume = {18},
number = {6},
pages = {635--645},
abstract = {Head injury resulting from blast loading, including mild traumatic brain injury, has been identified as an important blast-related injury in modern conflict zones. A study was undertaken to investigate potential protective ballistic helmet liner materials to mitigate primary blast injury using a detailed sagittal plane head finite element model, developed and validated against previous studies of head kinematics resulting from blast exposure. Five measures reflecting the potential for brain injury that were investigated included intracranial pressure, brain tissue strain, head acceleration (linear and rotational) and the head injury criterion. In simulations, these measures provided consistent predictions for typical blast loading scenarios. Considering mitigation, various characteristics of foam material response were investigated and a factor analysis was performed which showed that the four most significant were the interaction effects between modulus and hysteretic response, stress-strain response, damping factor and density. Candidate materials were then identified using the predicted optimal material values. Polymeric foam was found to meet the density and modulus requirements; however, for all significant parameters, higher strength foams, such as aluminum foam, were found to provide the highest reduction in the potential for injury when compared against the unprotected head.},
keywords = {*Blast Injuries/pc [Prevention \& Control], *Craniocerebral Trauma/pc [Prevention \& Control], *Explosions, *Head Protective Devices, Acceleration, Aluminum/ch [Chemistry], Biomechanical Phenomena, brain concussion, Brain Injuries, Brain/ph [Physiology], Computer simulation, CPD4NFA903 (Aluminum), Equipment Design, Head, Humans, intracranial pressure, Male, Materials testing},
pubstate = {published},
tppubtype = {article}
}
Hernandez, F; Shull, P B; Camarillo, D B
Evaluation of a laboratory model of human head impact biomechanics Journal Article
In: Journal of Biomechanics, vol. 48, no. 12, pp. 3469–3477, 2015.
Abstract | BibTeX | Tags: *HEAD, *Laboratories, *Mechanical Phenomena, *Models, Acceleration, Biological, Biomechanical Phenomena, Brain Concussion/et [Etiology], Football/in [Injuries], Head Protective Devices, Humans, Male, Neck/ph [Physiology], Rotation, SAFETY
@article{Hernandez2015,
title = {Evaluation of a laboratory model of human head impact biomechanics},
author = {Hernandez, F and Shull, P B and Camarillo, D B},
year = {2015},
date = {2015-01-01},
journal = {Journal of Biomechanics},
volume = {48},
number = {12},
pages = {3469--3477},
abstract = {This work describes methodology for evaluating laboratory models of head impact biomechanics. Using this methodology, we investigated: how closely does twin-wire drop testing model head rotation in American football impacts? Head rotation is believed to cause mild traumatic brain injury (mTBI) but helmet safety standards only model head translations believed to cause severe TBI. It is unknown whether laboratory head impact models in safety standards, like twin-wire drop testing, reproduce six degree-of-freedom (6DOF) head impact biomechanics that may cause mTBI. We compared 6DOF measurements of 421 American football head impacts to twin-wire drop tests at impact sites and velocities weighted to represent typical field exposure. The highest rotational velocities produced by drop testing were the 74th percentile of non-injury field impacts. For a given translational acceleration level, drop testing underestimated field rotational acceleration by 46% and rotational velocity by 72%. Primary rotational acceleration frequencies were much larger in drop tests ($sim$100 Hz) than field impacts ($sim$10 Hz). Drop testing was physically unable to produce acceleration directions common in field impacts. Initial conditions of a single field impact were highly resolved in stereo high-speed video and reconstructed in a drop test. Reconstruction results reflected aggregate trends of lower amplitude rotational velocity and higher frequency rotational acceleration in drop testing, apparently due to twin-wire constraints and the absence of a neck. These results suggest twin-wire drop testing is limited in modeling head rotation during impact, and motivate continued evaluation of head impact models to ensure helmets are tested under conditions that may cause mTBI. Copyright © 2015 Elsevier Ltd. All rights reserved.},
keywords = {*HEAD, *Laboratories, *Mechanical Phenomena, *Models, Acceleration, Biological, Biomechanical Phenomena, Brain Concussion/et [Etiology], Football/in [Injuries], Head Protective Devices, Humans, Male, Neck/ph [Physiology], Rotation, SAFETY},
pubstate = {published},
tppubtype = {article}
}
Swartz, E E; Broglio, S P; Cook, S B; Cantu, R C; Ferrara, M S; Guskiewicz, K M; Myers, J L
Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players Journal Article
In: Journal of Athletic Training, vol. 50, no. 12, pp. 1219–1222, 2015.
Abstract | BibTeX | Tags: *Craniocerebral Trauma/pc [Prevention & Control], *Football/in [Injuries], *Physical Education and Training/mt [Methods], Acceleration, Head Protective Devices, Humans, Male, Prospective Studies, Universities
@article{Swartz2015,
title = {Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players},
author = {Swartz, E E and Broglio, S P and Cook, S B and Cantu, R C and Ferrara, M S and Guskiewicz, K M and Myers, J L},
year = {2015},
date = {2015-01-01},
journal = {Journal of Athletic Training},
volume = {50},
number = {12},
pages = {1219--1222},
abstract = {OBJECTIVE: To test a helmetless-tackling behavioral intervention for reducing head impacts in National Collegiate Athletic Association Division I football players. DESIGN: Randomized controlled clinical trial. SETTING: Football field. PATIENTS OR OTHER PARTICIPANTS: Fifty collegiate football players (intervention = 25},
keywords = {*Craniocerebral Trauma/pc [Prevention \& Control], *Football/in [Injuries], *Physical Education and Training/mt [Methods], Acceleration, Head Protective Devices, Humans, Male, Prospective Studies, Universities},
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}
}
Wang, H; Wang, B; Jackson, K; Miller, C M; Hasadsri, L; Llano, D; Rubin, R; Zimmerman, J; Johnson, C; Sutton, B
A novel head-neck cooling device for concussion injury in contact sports Journal Article
In: Translational Neuroscience, vol. 6, pp. 20–31, 2015.
Abstract | Links | BibTeX | Tags: Acceleration, Article, brain concussion, Brain hypothermia, brain perfusion, brain temperature, brain tissue, clinical study, cognition, contact sport, cooling, diving, exercise, exercise induced hyperthermia, experimental study, government, head neck cooling device, Head-neck cooling, human, hyperthermia, induced hypothermia, mild traumatic brain injury, nonhuman, priority journal, randomized controlled trial (topic), sport injury, Sports, surface property, thermal regulating system, thermal stimulation, thermoregulation, traumatic brain injury
@article{Wang2015a,
title = {A novel head-neck cooling device for concussion injury in contact sports},
author = {Wang, H and Wang, B and Jackson, K and Miller, C M and Hasadsri, L and Llano, D and Rubin, R and Zimmerman, J and Johnson, C and Sutton, B},
doi = {10.1515/tnsci-2015-0004},
year = {2015},
date = {2015-01-01},
journal = {Translational Neuroscience},
volume = {6},
pages = {20--31},
abstract = {Emerging research on the long-term impact of concussions on athletes has allowed public recognition of the potentially devastating effects of these and other mild head injuries. Mild traumatic brain injury (mTBI) is a multifaceted disease for which management remains a clinical challenge. Recent pre-clinical and clinical data strongly suggest a destructive synergism between brain temperature elevation and mTBI; conversely, brain hypothermia, with its broader, pleiotropic effects, represents the most potent neuro-protectant in laboratory studies to date. Although well-established in selected clinical conditions, a systemic approach to accomplish regional hypothermia has failed to yield an effective treatment strategy in traumatic brain injury (TBI). Furthermore, although systemic hypothermia remains a potentially valid treatment strategy for moderate to severe TBIs, it is neither practical nor safe for mTBIs. Therefore, selective head-neck cooling may represent an ideal strategy to provide therapeutic benefits to the brain. Optimizing brain temperature management using a National Aeronautics and Space Administration (NASA) spacesuit spinoff head-neck cooling technology before and/or after mTBI in contact sports may represent a sensible, practical, and effective method to potentially enhance recover and minimize post-injury deficits. In this paper, we discuss and summarize the anatomical, physiological, preclinical, and clinical data concerning NASA spinoff head-neck cooling technology as a potential treatment for mTBIs, particularly in the context of contact sports. © 2015 Huan Wang et al., licensee De Gruyter Open.},
keywords = {Acceleration, Article, brain concussion, Brain hypothermia, brain perfusion, brain temperature, brain tissue, clinical study, cognition, contact sport, cooling, diving, exercise, exercise induced hyperthermia, experimental study, government, head neck cooling device, Head-neck cooling, human, hyperthermia, induced hypothermia, mild traumatic brain injury, nonhuman, priority journal, randomized controlled trial (topic), sport injury, Sports, surface property, thermal regulating system, thermal stimulation, thermoregulation, traumatic brain injury},
pubstate = {published},
tppubtype = {article}
}
Caryn, R C; Hazell, T J; Dickey, J P
Transmission of acceleration from a synchronous vibration exercise platform to the head Journal Article
In: International Journal of Sports Medicine, vol. 35, no. 4, pp. 330–338, 2014.
Abstract | BibTeX | Tags: *Exercise/ph [Physiology], *HEAD, *Knee Joint/ph [Physiology], *Posture/ph [Physiology], *Sports Equipment, *Vibration, Acceleration, adult, Humans, Male
@article{Caryn2014,
title = {Transmission of acceleration from a synchronous vibration exercise platform to the head},
author = {Caryn, R C and Hazell, T J and Dickey, J P},
year = {2014},
date = {2014-01-01},
journal = {International Journal of Sports Medicine},
volume = {35},
number = {4},
pages = {330--338},
abstract = {Exercise vibration platforms are becoming commonplace in homes and fitness centers. However, excessive mechanical energy transferred to the head and eye can cause injury. The purpose of this study was to evaluate how changes in platform frequency and knee flexion angle affect acceleration transmission to the head. Participants (N=12) stood on a whole-body vibration platform with knee flexion angles of 0degree, 20degree, and 40degree to evaluate how changes in knee flexion affected head acceleration. 7 specific platform frequencies were tested between 20-50Hz at 2 peak-to-peak displacement settings (1 and 2mm nominal). Accelerations were measured with triaxial accelerometers at the platform and head to generate transmissibility ratios. Platform-to-head transmissibility was not significantly different between the 2 platform peak-to-peak amplitudes (P\>0.05). Transmissibility measures varied depending on platform frequency and knee angle (P\<0.05). Flexing the knees resulted in reduced head transmissibility at all frequencies (P\<0.05). Platform-to-head transmissibility values exceeded 1.0 at both 20 and 25Hz platform vibration frequencies with the knees in full extension. To reduce the risk of injury to structures of the head during vibration exercise, using platforms frequencies below 30Hz with small knee flexion angles (\<40degree) should be avoided. Copyright © Georg Thieme Verlag KG Stuttgart . New York.},
keywords = {*Exercise/ph [Physiology], *HEAD, *Knee Joint/ph [Physiology], *Posture/ph [Physiology], *Sports Equipment, *Vibration, Acceleration, adult, Humans, Male},
pubstate = {published},
tppubtype = {article}
}
Wu, L C; Zarnescu, L; Nangia, V; Cam, B; Camarillo, D B
A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard Journal Article
In: IEEE Transactions on Biomedical Engineering, vol. 61, no. 11, pp. 2659–2668, 2014.
Abstract | BibTeX | Tags: *Biomechanical Phenomena/ph [Physiology], *Head/ph [Physiology], *Monitoring, *Mouth Protectors, *Support Vector Machine, Acceleration, Accelerometry/is [Instrumentation], Ambulatory/is [Instrumentation], Ambulatory/mt [Methods], Closed, Computer-Assisted/is [Instrumen, football, Head Injuries, Humans, Infrared Rays, Monitoring, Reproducibility of Results, Sensitivity and Specificity, Signal Processing
@article{Wu2014,
title = {A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard},
author = {Wu, L C and Zarnescu, L and Nangia, V and Cam, B and Camarillo, D B},
year = {2014},
date = {2014-01-01},
journal = {IEEE Transactions on Biomedical Engineering},
volume = {61},
number = {11},
pages = {2659--2668},
abstract = {Injury from blunt head impacts causes acute neurological deficits and may lead to chronic neurodegeneration. A head impact detection device can serve both as a research tool for studying head injury mechanisms and a clinical tool for real-time trauma screening. The simplest approach is an acceleration thresholding algorithm, which may falsely detect high-acceleration spurious events such as manual manipulation of the device. We designed a head impact detection system that distinguishes head impacts from nonimpacts through two subsystems. First, we use infrared proximity sensing to determine if the mouthguard is worn on the teeth to filter out all off-teeth events. Second, on-teeth, nonimpact events are rejected using a support vector machine classifier trained on frequency domain features of linear acceleration and rotational velocity. The remaining events are classified as head impacts. In a controlled laboratory evaluation, the present system performed substantially better than a 10-g acceleration threshold in head impact detection (98% sensitivity, 99.99% specificity, 99% accuracy, and 99.98% precision, compared to 92% sensitivity, 58% specificity, 65% accuracy, and 37% precision). Once adapted for field deployment by training and validation with field data, this system has the potential to effectively detect head trauma in sports, military service, and other high-risk activities.},
keywords = {*Biomechanical Phenomena/ph [Physiology], *Head/ph [Physiology], *Monitoring, *Mouth Protectors, *Support Vector Machine, Acceleration, Accelerometry/is [Instrumentation], Ambulatory/is [Instrumentation], Ambulatory/mt [Methods], Closed, Computer-Assisted/is [Instrumen, football, Head Injuries, Humans, Infrared Rays, Monitoring, Reproducibility of Results, Sensitivity and Specificity, Signal Processing},
pubstate = {published},
tppubtype = {article}
}
McIntosh, A S; Lai, A; Schilter, E
Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests Journal Article
In: Traffic Injury Prevention, vol. 14, no. 5, pp. 501–508, 2013.
Abstract | BibTeX | Tags: *Accidents, *Bicycling/in [Injuries], *Craniocerebral Trauma/et [Etiology], *Head Protective Devices/ut [Utilization], Acceleration, Biological, Biomechanical Phenomena, Computer simulation, Humans, Male, Manikins, Models, Traffic/sn [Statistics & Numerical Dat
@article{McIntosh2013,
title = {Bicycle helmets: head impact dynamics in helmeted and unhelmeted oblique impact tests},
author = {McIntosh, A S and Lai, A and Schilter, E},
year = {2013},
date = {2013-01-01},
journal = {Traffic Injury Prevention},
volume = {14},
number = {5},
pages = {501--508},
abstract = {OBJECTIVE: To assess the factors, including helmet use, that contribute to head linear and angular acceleration in bicycle crash simulation tests. METHOD: A series of laboratory tests was undertaken using an oblique impact rig. The impact rig included a drop assembly with a Hybrid III head and neck. The head struck a horizontally moving striker plate. Head linear and angular acceleration and striker plate force were measured. The Head Injury Criterion was derived. The following test parameters were varied: drop height to a maximum of 1.5 m, horizontal speed to a maximum of 25 km/h, helmet/no helmet, impact orientation/location, and restraint adjustment. Additional radial impacts were conducted on the same helmet models for comparison purposes. Descriptive statistics were derived and multiple regression was applied to examine the role of each parameter. RESULTS: Helmet use was the most significant factor in reducing the magnitude of all outcome variables. Linear acceleration and the Head Injury Criterion were influenced by the drop height, whereas angular acceleration tended to be influenced by the horizontal speed and impact orientation/location. The restraint adjustment influenced the outcome variables, with lower coefficients of variation observed with the tight restraint. CONCLUSIONS: The study reinforces the benefits of wearing a bicycle helmet in a crash. The study also demonstrates that helmets do not increase angular head acceleration. The study assists in establishing the need for an agreed-upon international oblique helmet test as well as the boundary conditions for oblique helmet testing.},
keywords = {*Accidents, *Bicycling/in [Injuries], *Craniocerebral Trauma/et [Etiology], *Head Protective Devices/ut [Utilization], Acceleration, Biological, Biomechanical Phenomena, Computer simulation, Humans, Male, Manikins, Models, Traffic/sn [Statistics \& Numerical Dat},
pubstate = {published},
tppubtype = {article}
}
Ivancic, P C
Neck injury response to direct head impact Journal Article
In: Accident Analysis & Prevention, vol. 50, pp. 323–329, 2013.
Abstract | BibTeX | Tags: *Accidents, *Neck Injuries/et [Etiology], *Neck Injuries/pp [Physiopathology], Acceleration, ANALYSIS of variance, Biomechanical Phenomena, Cadaver, Humans, Manikins, Rotation, Traffic, VIDEO recording
@article{Ivancic2013,
title = {Neck injury response to direct head impact},
author = {Ivancic, P C},
year = {2013},
date = {2013-01-01},
journal = {Accident Analysis \& Prevention},
volume = {50},
pages = {323--329},
abstract = {Previous in vivo studies have observed flexion of the upper or upper/middle cervical spine and extension at inferior spinal levels due to direct head impacts. These studies hypothesized that hyperflexion may contribute to injury of the upper or middle cervical spine during real-life head impact. Our objectives were to determine the cervical spine injury response to direct head impact, document injuries, and compare our results with previously reported in vivo data. Our model consisted of a human cadaver neck (n=6) mounted to the torso of a rear impact dummy and carrying a surrogate head. Rearward force was applied to the model's forehead using a cable and pulley system and free-falling mass of 3.6kg followed by 16.7kg. High-speed digital cameras tracked head, vertebral, and pelvic motions. Average peak spinal rotations observed during impact were statistically compared (P\<0.05) to physiological ranges obtained from intact flexibility tests. Peak head impact force was 249 and 504N for the 3.6 and 16.7kg free-falling masses, respectively. Occipital condyle loads reached 205.3N posterior shear, 331.4N compression, and 7.4Nm extension moment. We observed significant increases in intervertebral extension peaks above physiologic at C6/7 (26.3degree vs. 5.7degree) and C7/T1 (29.7degree vs. 4.6degree) and macroscopic ligamentous and osseous injuries at C6 through T1 due to the 504N impacts. Our results indicate that a rearward head shear force causes complex neck loads of posterior shear, compression, and extension moment sufficient to injure the lower cervical spine. Real-life neck injuries due to motor vehicle crashes, sports impacts, or falls are likely due to combined loads transferred to the neck by direct head impact and torso inertial loads. Copyright © 2012 Elsevier Ltd. All rights reserved.},
keywords = {*Accidents, *Neck Injuries/et [Etiology], *Neck Injuries/pp [Physiopathology], Acceleration, ANALYSIS of variance, Biomechanical Phenomena, Cadaver, Humans, Manikins, Rotation, Traffic, VIDEO recording},
pubstate = {published},
tppubtype = {article}
}
McLeod, P; Reed, N; Gilson, S; Glennerster, A
How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality Journal Article
In: Vision Research, vol. 48, no. 13, pp. 1479–1487, 2008.
Abstract | BibTeX | Tags: *Head Movements/ph [Physiology], *Motion Perception/ph [Physiology], *Soccer/ph [Physiology], Acceleration, adult, Humans, Male, psychomotor performance, Reaction Time/ph [Physiology], User-Computer Interface
@article{McLeod2008,
title = {How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality},
author = {McLeod, P and Reed, N and Gilson, S and Glennerster, A},
year = {2008},
date = {2008-01-01},
journal = {Vision Research},
volume = {48},
number = {13},
pages = {1479--1487},
abstract = {We measured the movements of soccer players heading a football in a fully immersive virtual reality environment. In mid-flight the ball's trajectory was altered from its normal quasi-parabolic path to a linear one, producing a jump in the rate of change of the angle of elevation of gaze (alpha) from player to ball. One reaction time later the players adjusted their speed so that the rate of change of alpha increased when it had been reduced and reduced it when it had been increased. Since the result of the player's movement was to regain a value of the rate of change close to that before the disturbance, the data suggest that the players have an expectation of, and memory for, the pattern that the rate of change of alpha will follow during the flight. The results support the general claim that players intercepting balls use servo control strategies and are consistent with the particular claim of Optic Acceleration Cancellation theory that the servo strategy is to allow alpha to increase at a steadily decreasing rate.},
keywords = {*Head Movements/ph [Physiology], *Motion Perception/ph [Physiology], *Soccer/ph [Physiology], Acceleration, adult, Humans, Male, psychomotor performance, Reaction Time/ph [Physiology], User-Computer Interface},
pubstate = {published},
tppubtype = {article}
}
Hamberger, A; Huang, Y L; Zhu, H; Bao, F; Ding, M; Blennow, K; Olsson, A; Hansson, H A; Viano, D; Haglid, K G
Redistribution of neurofilaments and accumulation of beta-amyloid protein after brain injury by rotational acceleration of the head Journal Article
In: Journal of Neurotrauma, vol. 20, no. 2, pp. 169–178, 2003.
Abstract | BibTeX | Tags: *Amyloid beta-Peptides/me [Metabolism], *Brain Injuries/me [Metabolism], *Brain/me [Metabolism], *Neurofilament Proteins/me [Metabolism], 0 (Amyloid beta-Peptides), 0 (neurofilament protein L), 0 (Neurofilament Proteins), 108688-71-7 (neurofilament protein H), Acceleration, Animals, Brain Injuries/et [Etiology], immunohistochemistry, Phosphorylation, Rabbits, Rotation, Tissue Distribution
@article{Hamberger2003,
title = {Redistribution of neurofilaments and accumulation of beta-amyloid protein after brain injury by rotational acceleration of the head},
author = {Hamberger, A and Huang, Y L and Zhu, H and Bao, F and Ding, M and Blennow, K and Olsson, A and Hansson, H A and Viano, D and Haglid, K G},
year = {2003},
date = {2003-01-01},
journal = {Journal of Neurotrauma},
volume = {20},
number = {2},
pages = {169--178},
abstract = {Rotational acceleration of the head, as occurs in falls, car crashes, and sport injuries, may result in diffuse brain damage, with acute and chronic neurological and psychiatric symptoms. The present study addresses the effects of rotational trauma on the neuronal cytoskeleton, which stabilizes perikaryal, dendritic and axonal shape and function. The study focuses upon the distribution of (1) the phosphorylated form of the heavy neurofilament subunit, (2) the light neurofilament subunit, and (3) beta-amyloid, a marker for brain injury. While normally restricted to axons, the phosphorylated heavy neurofilament subunits were drastically decreased in the axons after rotational trauma. Instead, they accumulated in the neuronal perikarya, normally devoid of the phosphorylated subunit. This alteration was seen, not only in the cerebral cortex, but also in the hippocampus, the cervical spinal cord, the cerebellum, the cranial nerves and the pyramidal tract. The distribution of the light subunit of neurofilaments was also altered post trauma. Only a weak beta-amyloid immunoreactivity was detected in the brains of control animals. Promptly after the trauma, a large number of beta-amyloid positive neurons appeared. Intensely co-localized immunoreactivity for the light subunit of neurofilaments and of beta-amyloid was seen 3 days after the rotational trauma axons of in the subcortical white matter and in the granule cell layer of the dentate gyrus as well as in neurons of the hypoglossal nucleus. The reported alterations in the central nervous system neurons are similar to those in the human brain after closed head injury and in chronic degenerative diseases. Regions of importance for social behavior, memory and body movement were affected.},
keywords = {*Amyloid beta-Peptides/me [Metabolism], *Brain Injuries/me [Metabolism], *Brain/me [Metabolism], *Neurofilament Proteins/me [Metabolism], 0 (Amyloid beta-Peptides), 0 (neurofilament protein L), 0 (Neurofilament Proteins), 108688-71-7 (neurofilament protein H), Acceleration, Animals, Brain Injuries/et [Etiology], immunohistochemistry, Phosphorylation, Rabbits, Rotation, Tissue Distribution},
pubstate = {published},
tppubtype = {article}
}
McLean, A J
Brain injury without head impact? Journal Article
In: Journal of Neurotrauma, vol. 12, no. 4, pp. 621–625, 1995.
Abstract | BibTeX | Tags: *Brain Injuries/et [Etiology], Acceleration, Accidents, autopsy, Brain Injuries/mo [Mortality], cause of death, Head, Humans, Mechanical, Nonpenetrating, Stress, Traffic, Wounds
@article{McLean1995,
title = {Brain injury without head impact?},
author = {McLean, A J},
year = {1995},
date = {1995-01-01},
journal = {Journal of Neurotrauma},
volume = {12},
number = {4},
pages = {621--625},
abstract = {The proposition that acceleration of the brain without direct impact to the head can result in brain injury is examined by reviewing a series of 414 road users who were fatally injured in the vicinity of Adelaide, South Australia. The series comprises 170 pedestrians, 10 pedal cyclists, 143 motorcyclists, and 91 vehicle occupants. In each case a member of the research team attended the autopsy to look for evidence of impact on the body, particularly to the head or face. The brain was examined by a neuropathologist and the type and pattern of injury was recorded. The circumstances of the crash were investigated, including an examination of the crash site and the vehicles involved and, where relevant, interviews with witnesses. In cases involving a motorcyclist the helmet worn was retrieved by the police and assigned to the research unit for examination. Particular attention was paid to the identification of objects causing injury to the head or face and also to objects impacted by a helmet. Brain injury was recorded as a cause of death in 55% of the 403 cases for which there was a clear classification of cause of death. Brain injury, at any level of severity, was identified by a neuropathologist in 86 percent of the 414 fatally injured road users in the sample, including 24 cases that were examined microscopically. There were no cases in which there was an injury to the brain in the absence of evidence of an impact to the head.},
keywords = {*Brain Injuries/et [Etiology], Acceleration, Accidents, autopsy, Brain Injuries/mo [Mortality], cause of death, Head, Humans, Mechanical, Nonpenetrating, Stress, Traffic, Wounds},
pubstate = {published},
tppubtype = {article}
}