Occurrence Of Concussion Research Articles

Concussion history is associated with poor sleep quality in adolescent athletes: a cross-sectional study.

Whereas previous research has primarily focused on the immediate effects of concussion within the first year postinjury, this study examines the persistent effects of concussion on subsequent sleep quality in adolescent soccer players. This study used a cross-sectional design, recruiting a convenience sample of adolescent athletes from US Youth Soccer camps. Participants completed a self-reported questionnaire including the Pittsburgh Sleep Quality Index to assess their sleep quality. Athletes were also asked to report sport participation information, any past occurrence of concussion or knee injury, and any sport-related injury in the past 12 months. Independent samples t tests were performed to identify significant differences in Pittsburgh Sleep Quality Index scores between injured and noninjured participants. A total of 177 participants (103 male, 14.61 ± 1.88 years of age) were included in the analysis. The concussion injury group exhibited later bedtimes (difference: 0.32 ± 0.05 hours, P = .047), fewer hours of sleep (difference: 0.56 ± 0.11 hours, P = .015), and more frequent sleep disturbances (P = .012). Furthermore, these athletes reported lengthened sleep latency (difference: 2.55 ± 3.36 minutes, P = .016) and higher levels of daytime dysfunction (P = .041) following their concussion injuries. Moreover, athletes in the concussion injury group displayed worse sleep quality scores (difference: 0.42 ± 0.06, P < .001) and higher total Pittsburgh Sleep Quality Index scores (difference: 1.91 ± 0.41, P < .001). No significant differences were found based on past knee injury or sport-related injury in the past 12 months. These findings suggest the need for targeted interventions aimed at improving sleep quality in adolescent athletes with a history of concussion. Sahin S, Erdman AL, Loewen A, etal. Concussion history is associated with poor sleep quality in adolescent athletes: a cross-sectional study. J Clin Sleep Med. 2025;21(1):129-135.

Ethical concerns in integrating sport-related concussion (SRC) genetic testing into return-to-play (RTP) protocols

ABSTRACT The occurrence of sport-related concussions (SRCs) has emerged as a significant health concern in professional sports, with millions of concussions occurring worldwide each year. Current return-to-play (RTP) protocols after SRCs involve a multi-disciplinary approach with growing interest in genetic testing technology. Numerous studies have indicated that the gene Apolipoprotein E4 (APOE4) holds promise as a predictive factor for developing diseases after concussions and other traumatic brain injuries. Nevertheless, there is an ongoing and contentious debate surrounding the impact of SRC genetic testing on the RTP decision, encompassing concerns about the potential adverse effects on individual athletes, coaches, and even the whole sport community at large not in a small degree due to incidental findings. Hence, the purpose of this article is to explore the clinical and ethical components of SRCs genetic testing and its potential integration into RTP protocols by utilizing the ACCE framework to assess the validity, utility, and ethical aspects of SRCs.

Structure-property relationships of velar bone tissue from the energy absorbing horncore of bighorn sheep rams.

Velar bone is the material that fills the horncore of bighorn sheep rams. The architectural dimensions of velar bone are orders of magnitude larger than trabecular bone, and velae are more sail-like compared to strut-like trabeculae. Velar bone is important for energy absorption and reduction of brain cavity accelerations during high energy head impacts, but velar bone material properties were previously unknown. It was hypothesized that velar bone tissue would have properties that are beneficial for increased energy absorption at the material level. Solid velar bone beams were tested using dynamic mechanical analysis and three-point bending to quantify mechanical properties. Additionally, the porosity, osteon population density, and mineral content of the solid velar sails were quantified. The velar bone damping factor (∼0.03 - 0.06) and modulus of toughness (3.9 ± 0.4 MJ/m3) were lower than other mammalian cortical bone tissues. The solid bony sails have a bending modulus (8.6 ± 0.5 GPa) that lies within the range of bending moduli values previously reported for individual trabecular struts and cortical bone tissue. The solid velar bone sails had porosity (6.7 ± 0.9 %) and bone mineral content (66 ± 1 %) in the range of cortical bone values. Interestingly, velar sails contained osteons, which are rarely found in trabecular struts. The velar bone osteon population density (5.8 ± 0.9 osteons/mm2) is in the low end of the range of values reported for cortical bone in other mammals. STATEMENT OF SIGNIFICANCE: Bighorn sheep rams sustain high energy head impacts during intraspecific combat without overt signs of brain injury. Previous studies have shown that the bony horncore plays a critical role in energy absorption and reduction of brain cavity accelerations post impact, which has implications for concussion prevention in humans. However, the material properties of the horncore velar bone were previously unknown. This study quantified the material properties and structure-property relationships of the horncore velar bone at the tissue level. Results from this study will improve our understanding of how bighorn sheep mitigate brain injury during head-to-head impacts and may inspire the design of novel materials for energy absorption applications (i.e., helmets materials that reduce concussion occurrence in humans).

Paper 60: Effect of Mouthguard Type on Severity of Concussion During Game-Related College Football Competition. A 16-Season Prospective Study

Objectives: Prior studies have either claimed or disputed the role of mouthguard protection in reducing the incidence of concussion. Other than investigating a decrease in concussion rate, no long term studies have specifically compared the effect of type of mouthguard protection on the severity of concussion. The increasing incidence of head trauma in sport, the potential for long-term traumatic brain injury, and concerns of rising medical costs, dictate a focus on variables that may influence concussion severity in contact sports. Therefore, this study quantified the effect of mouthguard type on severity of concussion during game-related college football competition. Methods: 40 universities were evaluated over 16 competitive seasons (2006-2021) across all Football Bowl Subdivision (FBS) conferences. Mouthguard type was divided into two groups based on dentist- fitted and self-fitted (generic/boil and bite). Outcomes of interest included concussion severity (simple: 0-10 days time loss, complex: &gt; 10 days time loss), injury category, player position, injury situation, injury mechanism, elective imaging, and playing surface. Data were subject to multivariate analyses of variance (MANOVA) and Wilks’ λ criteria using GLM procedures, and expressed as incidence rates (lR) per 10 game season. Results: Of the 2,332 games documented, 9,563 total injuries were reported, resulting in 708 (589 simple, 119 complex) concussion cases, consisting of 653 player-to-player contacts and 55 player-to- surface impacts. MANOVA indicated significant main effects of mouthguard type by concussion severity ( F1,705 = 3.587; P = .028), player position by team ( F2,705 = 3.551; P = .029), player position by skill position ( F8,699 = 2.373; P = .016), and injury mechanism ( F6,701 = 4.467; P &lt; .001). Post hoc analyses indicated a significantly lower ( P = .023) incidence of complex concussions [1.3, (95% CI, 0.9-1.6) vs 2.1 (1.7-2.5)], with a significantly higher ( P = 0.014) occurrence of simple concussions [8.7, (95% CI, 8.4-9.1) vs 7.9 (7.5- 8.3)] while wearing dentist-fitted versus self-fitted mouthguards, respectively. Although significantly greater ( P &lt;.05) incidences of concussion were documented across offensive teams [4.3, (95% CI, 3.8- 4.8) vs 3.3 (2.9-3.8)], quarterbacks [0.9, (95% CI, 0.6-1.2) vs 0.3 (0.2-0.6)], and players tackled above the waist [2.8, (95% CI, 2.4-3.3) vs 1.7 (1.4-2.1)] than observed across other teams and injury mechanisms while wearing dentist-fitted as compared to self-fitted mouthguards, respectively. The majority of these cases, however, were diagnosed as simple concussions. Of the 1,150 games (49.3%) played on a 3-layer artificial turf (≥9.0 lbs/ft2) infill system and 1,182 games (50.7%) played on natural grass, surface-related concussions on artificial turf (n = 26; 3.7% of total concussions; 21 simple, 5 complex concussions) and natural grass (n = 30; 4.2 % of total concussions; 23 simple, 7 complex concussions) were minimal and less severe on both surfaces than often perceived. Conclusions: The significantly lower incidence of complex concussions documented with dentist-fitted mouthguards during college football competition may reflect greater shock absorption and redistribution of energy during head impact due to more optimal fit and fabrication when compared to self-fitted mouth protection, translating to less severity of trauma and more expedient return to play. This longitudinal study directly compares and addresses type of mouthguards as they relate specifically to concussion severity. Although findings of this study may be generalizable only to this level of football competition, further research is warranted into lower levels of competition, e.g., high school, youth football, where the use of self-fitted mouthguards is prevalent.

Subtle impairments of perceptual-motor function and well-being are detectable among military cadets and college athletes with self-reported history of concussion.

A lack of obvious long-term effects of concussion on standard clinical measures of behavioral performance capabilities does not preclude the existence of subtle neural processing impairments that appear to be linked to elevated risk for subsequent concussion occurrence, and which may be associated with greater susceptibility to progressive neurodegenerative processes. The purpose of this observational cohort study was to assess virtual reality motor response variability and survey responses as possible indicators of suboptimal brain function among military cadets and college athletes with self-reported history of concussion (HxC). The cohort comprised 75 college students (20.7 ± 2.1 years): 39 Reserve Officer Training Corp (ROTC) military cadets (10 female), 16 football players, and 20 wrestlers; HxC self-reported by 20 (29.2 ± 27.1 months prior, range: 3-96). A virtual reality (VR) test involving 40 lunging/reaching responses to horizontally moving dots (filled/congruent: same direction; open/incongruent: opposite direction) was administered, along with the Sport Fitness and Wellness Index (SFWI) survey. VR Dispersion (standard deviation of 12 T-scores for neck, upper extremity, and lower extremity responses to congruent vs. incongruent stimuli originating from central vs. peripheral locations) and SFWI response patterns were the primary outcomes of interest. Logistic regression modeling of VR Dispersion (range: 1.5-21.8), SFWI (range: 44-100), and an interaction between them provided 81% HxC classification accuracy (Model χ 2[2] = 26.03, p < .001; Hosmer & Lemeshow χ 2[8] = 1.86, p = .967; Nagelkerke R 2 = .427; Area Under Curve = .841, 95% CI: .734, .948). Binary modeling that included VR Dispersion ≥3.2 and SFWI ≤86 demonstrated 75% sensitivity and 86% specificity with both factors positive (Odds Ratio = 17.6, 95% CI: 5.0, 62.1). Detection of subtle indicators of altered brain processes that might otherwise remain unrecognized is clearly important for both short-term and long-term clinical management of concussion. Inconsistency among neck, upper extremity, and lower extremity responses to different types of moving visual stimuli, along with survey responses suggesting suboptimal well-being, merit further investigation as possible clinical indicators of persisting effects of concussion that might prove to be modifiable.

Electrophysiology reveals cognitive-linguistic alterations after concussion

Language deficits and alterations to the N400 ERP are commonly reported in aphasia and moderate-to-severe traumatic brain injury (TBI), but have seldomly been investigated after mild TBI, such as concussion. In the present study, the N400 was recorded from young adults within 1-month after concussion and matched controls during a sentence processing task. The N400 recorded to semantically incongruent sentence-final words was significantly more negative and with a more anterior distribution in the concussion group than control group. Among the concussion group, a weaker N400 was associated with more concussion symptoms, slower response time, and poorer executive functioning. Multiple regression results showed that concussion occurrence and male gender were independently associated with a more negative N400-effect, whereas symptoms were associated with a weaker N400. These findings provide novel evidence that alterations to lexical-semantic networks may occur after concussion and vary based on individual differences in post-concussion symptoms and cognitive function.

Sports-Related Concussions in Adults Presenting to Canadian Emergency Departments.

To document the occurrence and recovery outcomes of sports-related concussions (SRCs) presenting to the Emergency Department (ED) in a community-based sample. A prospective observational cohort study was conducted in 3 Canadian hospitals. Emergency Department. Adults (≥17 years) presenting with a concussion to participating EDs with a Glasgow Coma Scale score ≥13 were recruited. Patient demographics (eg, age and sex), clinical characteristics (eg, history of depression or anxiety), injury characteristics (eg, injury mechanisms and loss of consciousness and duration), and ED management and outcomes (eg, imaging, consultations, and ED length of stay) were collected. Patients' self-reported persistent concussion symptoms, return to physical activity status, and health-related quality of life at 30 and 90 days after ED discharge. Overall, 248 patients were enrolled, and 25% had a SRC. Patients with SRCs were younger and reported more physical activity before the event. Although most of the patients with SRCs returned to their normal physical activities at 30 days, postconcussive symptoms persisted in 40% at 90 days of follow-up. After adjustment, there was no significant association between SRCs and persistent symptoms; however, patients with concussion from motor vehicle collisions were more likely to have persistent symptoms. Although physically active individuals may recover faster after a concussion, patients returning to their physical activities before full resolution of symptoms are at higher risk of persistent symptoms and further injury. Patient-clinician communications and tailored recommendations should be encouraged to guide appropriate acute management of concussions.

Efficacy of Softball Face Masks at Reducing Linear and Rotational Head Acceleration

This research study looked at the efficacy of infield softball face masks at reducing concussion risk. The primary goal of this research was to contrast head accelerations experienced during softball impacts for different brands of softball face masks. In order to achieve this goal, a surrogate headform equipped with different brands of face masks was impacted at a constant impact location and ball speed. The resulting headform accelerations (linear and rotational) were collected with a Vernier accelerometer upon each impact and analyzed. The results of the study showed that all tested brands of face masks were successful at reducing head acceleration severity. Moreover, significant differences in performance were observed between the different brands of face masks. One can conclude from this research that particular brands of face masks can more effectively reduce concussion risk because they better reduce head acceleration values. Due to the study results, softball players may have a better understanding of face mask performance, which could lead to higher mask implementation in the sport and an overall reduction in softball-related concussion occurrence.

A Routine Electroencephalography Monitoring System for Automated Sports-Related Concussion Detection.

Cases of concussions in the United States keep increasing and are now up to 2 million to 3 million incidents per year. Although concussions are recoverable and usually not life-threatening, the degree and rate of recovery may vary depending on age, severity of the injury, and past concussion history. A subsequent concussion before full recovery may lead to more-severe brain damage and poorer outcomes. Electroencephalography (EEG) recordings can identify brain dysfunctionality and abnormalities, such as after a concussion. Routine EEG monitoring can be a convenient method for reducing unreported injuries and preventing long-term damage, especially among groups with a greater risk of experiencing a concussion, such as athletes participating in contact sports. Because of the relative availability of EEG compared to other brain-imaging techniques (e.g., functional magnetic resonance imaging), the use of EEG monitoring is growing for various neurological disorders. In this longitudinal study, EEG was analyzed from 4 football athletes before their athletic season and also within 7 days of concussion. Compared to a control group of 4 additional athletes, a concussion was detected with up to 99.5% accuracy using EEG recordings in the Theta-Alpha band. Classifiers that use data from only a subset of the EEG electrodes providing reliable detection are also proposed. The most effective classifiers used EEG recordings from the Central scalp region in the Beta band and over the Temporal scalp region using the Theta-Alpha band. This proof-of-concept study and preliminary findings suggest that EEG monitoring may be used to identify a sports-related concussion occurrence with a high level of accuracy and thus reduce the chance of unreported concussion.

Evaluating the Performance of a Hockey Helmet in Mitigating Concussion Risk Using Measures of Acceleration and Energy During Simulated Free Fall

Hockey helmets represent the best form of head protection available to reduce the occurrence of skull fracture and concussion. Currently, helmet testing protocols focus on the reduction of peak linear acceleration measures. Gaps exist in analyzing how certain impact factors such as angle, neck stiffness, and location influence the energy loaded to the helmet and the risk of injury during head collisions. This study examined the effect of helmet impact angle, neck stiffness-torque levels, and helmet impact locations on energy reduction and risk of head injury grounded on acceleration measures using simulated free fall head collisions. The researchers conducted 540 impacts to collect the data. The results revealed statistical interaction effects between the angle of impact and location on measures of energy and risk of head injury. This study builds on existing literature by introducing an energy measurement technique to assess helmet performance. The outcome also provides an avenue for helmet manufacturers to evaluate the performance of the helmet in reducing concussion risk.

A randomized trial comparing prescribed light exercise to standard management for emergency department patients with acute mild traumatic brain injury.

Persistent post-concussion symptoms (PCS) after a mild traumatic brain injury (mTBI) or concussion do not occur in the majority of patients sustaining such injuries, but when they do occur, they have significant functional consequences for patients. Delays in return to school, work, recreational, and social activities can deeply impact quality of life and have major long-term negative life consequences that are anything but mild, despite the classification of the initial injury. Predictive abilities to determine which patients will suffer PCS are currently poor, although certain presentation characteristics may be associated, such as age at injury, the occurrence and timing of prior concussions, the mechanism of injury, and others. Research into utilization of various biomarkers as predictive tools is underway but clear answers are still forthcoming.

Elevated Serum Interleukin-1β Levels in Male, but not Female, Collision Sport Athletes with a Concussion History.

It is increasingly reported that a history of concussion may be associated with chronic deleterious consequences. While the pathophysiology that contributes to these consequences is not well understood, neuroinflammation is postulated to be critical. Activation of multi-protein complexes termed inflammasomes, a key component of this inflammatory response, has been reported in more severe TBIs; however, it has not been investigated in milder TBIs, such as concussion. This study investigated serum levels of interleukin (IL)-1β and IL-18 (key proteins activated downstream of these inflammasomes) at acute, sub-acute, and chronic time-points post-concussion. We recruited 105 Australian footballers (65 male, 40 female) during the pre-season, then prospectively followed these players for the occurrence of concussion during the season. At baseline, 58 footballers reported a previous concussion history, and 47 reported no previous concussion history. Additionally, 25 players sustained a mid-season concussion and were sampled at 2, 6, and 13 days post-concussion. Serum levels of IL-1β and IL-18 were quantified using highly sensitive Simoa HD-X Analyzer assays. At baseline, IL-1β levels were higher in male, but not female, footballers with a previous concussion history compared with footballers with no concussion history. There was also a positive correlation between years of collision sport participation and IL-18 levels in males. No evidence was found in males or females to indicate that IL-1β or IL-18 levels differed at 2, 6, or 13 days post-concussion. These findings provide novel insights into potential sex-specific physiological consequences of concussion, and suggest that neuroinflammation may be persistent chronically following concussion in male athletes.

Concussion occurrence and recognition in professional boxing and MMA matches: toward a concussion protocol in combat sports

ABSTRACT Objectives: Determine, through video reviews, how often concussions occur in combat sport matches, what influence they have on the outcome, and how well non-physician personnel can be trained to recognize concussions. Methods: This is a retrospective video analysis by an 8-person panel of 60 professional fights (30 boxing and 30 mixed martial arts). Through video review, physician and non-physician personnel recorded details about each probable concussion and determined if and when they would have stopped the fight compared to the official stoppage time. Results: A concussion was recorded in 47/60 fights. The mean number of concussions per minute of fight time was 0.061 (0.047 for boxers and 0.085 for MMA). When stratifying by outcome of the bout, the mean number of concussions per minute for the winner was 0.010 compared to the loser at 0.111 concussions per minute. The fighter that sustained the first concussion ultimately lost 98% of the time. The physician and non-physician raters had high agreement regarding the number of concussions that occurred to each fighter per match. The physician raters judged that 24 of the 60 fights (11 boxing [37%]; 13 MMA [43%]) should have been stopped sooner than what occurred. Conclusion: Recognizing that the concussions often occur in combat sport matches, that the losing fighter almost always is concussed first and tends to sustain more concussions during the fight, along with the demonstration that non-physician personnel can be taught to recognize concussion, may guide policy changes that improve brain health in combat sports.

Behavioral Tackling Interventions Decrease Head Impact Frequency in American Football Players: A Critically Appraised Topic

Context: The rate of sport-related concussion diagnosis has significantly increased in recent years, which has created a need for injury prevention initiatives. There have been efforts put forth by researchers and American football organizations to teach athletes how to tackle properly in order to decrease the number of subconcussive head impacts and concussions. Clinical Question: Does the implementation of a behavioral tackling intervention decrease the head impact frequency in American football players? Clinical Bottom Line: There is moderate SORT Level B evidence to support the use of behavioral tackling interventions as a means for reducing head impact frequency in football athletes. All four included studies found a significant reduction in head impacts following a behavioral tackling intervention with study findings ranging from a 26–33% reduction in impact frequency. These findings were consistent in youth, high school, and college football players and for different types of behavioral tackling interventions. Therefore, these results indicate that behavioral tackling interventions have the potential to reduce the number of head impacts sustained by American football players, which may ultimately lead to a reduction in concussion occurrence as well.

Injuries in inline skater hockey

In Germany, Inline Skater Hockey (ISH) is played by about 7500 active players on inline skates with equipment comparable to ice hockey using a hard-plastic ball. The aim of this retrospective epidemiological cross-sectional study is to record the frequency and types of injuries in this sport, for which there is a lack of medically adequate studies in the literature. A questionnaire comprising 112 items was used to collect demographic data, injuries in eight body regions and defined overuse injuries. 274 ISH players with an average age of 24.5 ± 6.2 years and an exposure time of 2787 ± 2063 hours were examined. 5701 injuries were recorded, 60.5 % of which were minor bruises, abrasions and wounds. The total injury rate per1000 hours was 9.6 ± 17.7, with an injury-related break of 12.8 ± 21.8 weeks per player. Field players with visors had highly significantly fewer head injuries (2.8 ± 6.1 vs. 8.9 ± 13.1; p < 0.001) with highly significantly (p < 0.001) fewer lacerations, nasal bone fractures, eye injuries and dental injuries. There was a weak negative correlation between facial protection and number of head injuries (r = -0.386, p < 0.001). In conclusion, frequency and types of injuries in ISH are comparable to ice hockey during training. In accordance with ice hockey, protective equipment in ISH can significantly reduce the occurrence of head injuries. Preventive attention should be paid to the wearing of a full visor and to education about the occurrence of concussions despite the use of a protective helmet.

An International Exploration of the Effect of Media Portrayals of Postconcussion Management on Concussion Identification in the General Public.

Concussion portrayal in media broadcasts of sporting events may contribute to lack of public understanding regarding concussion. In total, 828 participants from Australia, New Zealand, and the United Kingdom completed a questionnaire assessing concussion knowledge. Participants were randomly assigned to either receive sports return-to-play (RTP) guideline information (RTP group) or not (no-RTP group). Participants viewed 12 short clips from televised rugby games and indicated whether they believed the player in each clip had sustained a concussion. Participants were then informed whether the player was removed, returned, or stayed in the game and again asked whether they thought a concussion had occurred. Probability of reporting a likely concussion over all videos was 65.6%. When told a player's possible concussion was managed by removal from the game, participants were more likely to change their response from "no" (no concussion) to "yes" (concussion) than from "yes" to "no." When told the player stayed or returned to the game, participants were more likely to change their response from "yes" (concussion) to "no" (no concussion) than from "no" to "yes." There was no significant main effect for RTP guideline manipulation or interaction effect with RTP information. Additional player's injury management information influenced participants' judgments of concussion occurrence. Results show that information provided via sports media broadcasts influenced viewers' perceptions of concussion and appropriate concussion management.

Randomized Controlled Trial of a Novel Peer Concussion-Education Program for Collegiate Athletes.

The National Collegiate Athletic Association and US Department of Defense have called for educational programs to change the culture of concussion reporting, increase reporting behavior, and enhance the safety of players and service members. To evaluate the effects of a novel peer concussion-education program (PCEP) in changing knowledge, attitudes, and norms about concussion reporting among collegiate student-athletes and assess program implementation. Randomized controlled trial and qualitative analysis of interviews. National Collegiate Athletic Association athletic teams from randomly selected colleges or universities. A total of 1614 male and female student-athletes from 60 teams at 10 colleges and universities and 8 athletic trainers. The PCEP intervention trains 2 peer concussion educators to provide 2 education modules to their teammates. Knowledge, attitudes (oneself and teammates), and concussion occurrence or reporting were assessed at baseline, postintervention, and 1 month later. Eight athletic trainers were interviewed about program implementation. Compared with the control group, the intervention group showed greater increases occurred postintervention and at 1 month in concussion knowledge (F1,2648 = 51.3, P < .0001), intention to report (oneself, F2,2633 = 82.3, P < .0001; teammates, F2,2624 = 53.9, P < .0001), return-to-play protocol knowledge, (F2,2632 = 28.4, P < .0001), direct subjective norms (oneself, F2,2625 = 51.7, P < .0001; teammates, F2,2644 = 40.6, P < .0001), direct perceived behavioral control (oneself, F2,2628 = 53.7, P < .0001; teammates, F2,2615 = 68.2, P < .0001), and indirect attitudes (oneself, F2,2626 = 47.1, P < .001; teammates, F2,2623 = 40.9, P < .0001). Peer concussion-education program participants discussed concussion more often with a teammate (F1,1396 = 13.96, P < .0001) or athletic staff (F1,1396 = 6.62, P < .001). Qualitative program analysis revealed both positive aspects of the PCEP and areas for improvement. The PCEP showed promise in increasing concussion knowledge, intention to report concussion, reporting a teammate's concussion, and facilitating attitudinal changes that support reporting among student-athletes.

The NCAA's Special Relationship with Student-Athletes as a Theory of Liability for Concussion-Related Injuries

The National Collegiate Athletic Association (NCAA) is the primary governing body of college athletics. Although the NCAA proclaims to protect student-athletes, an examination of its practices suggests that the organization has a troubling history of ignoring the harmful effects of concussions. Over one hundred years after the NCAA was established, and seventy years after the NCAA itself knew of the potential effects of concussions, the organization has done little to reduce the occurrence of concussions or to alleviate the potential effects that stem from repeated hits to the head. This Note argues for recognizing a special relationship between the NCAA and student-athletes that would allow these athletes to hold the NCAA liable for concussion-related injuries.

Proposed injury thresholds for concussion in equestrian sports

Equestrian helmets are designed to pass certification standards based on linear drop tests onto rigid steel surfaces. However, concussions in equestrian sports occur most commonly when a rider is thrown off a horse and obliquely impacts a compliant surface such as turf or sand. This paper seeks to elucidate the mechanics of such impacts and thereby propose corresponding thresholds for the occurrence of concussion that can improve equestrian helmet standards and designs. The present study examined the biomechanics of real-world equestrian accidents and developed thresholds for the occurrence of concussive injury. Twenty-five concussive and 25 non-concussive falls in equestrian sports were reconstructed using a combination of video analysis, computational and physical reconstruction methods. These represented male and female accidents from horse racing and the cross-country phase of eventing. The resulting thresholds for concussion [59g, 2700rad/s2, 28rad/s, 0.24 (MPS), 6.6kPa and 0.27 (CSMD10) for 50% risk] were consistent with those reported in the literature and represent a unique combination of head kinematic thresholds compared to other sports. Current equestrian helmet standards commonly use a threshold of 250g and a linear drop to a steel anvil resulting in less than 15ms impacts. This investigation found that concussive equestrian accidents occurred from oblique impacts to turf or sand with lower magnitude and longer duration impacts (<130g and >20ms). This suggests that current equestrian helmet standards may not adequately represent real-world concussive impact conditions and, consequently, there is an urgent need to assess the protective capacity of equestrian helmets under real-world conditions.

Characteristics and factors of concussion events for tacklers in collegiate rugby union.

The purpose of this study was to determine the factors related to the occurrence of concussion in rugby tacklers. Match video records showing tackles leading to concussion were used to identify injury-inciting events. Additionally, noninjury tackles by concussed tacklers (prior to concussion) and position-matched tacklers from the same matches were used as a control cohort. All tackles were coded according to the tackling characteristics. The odds ratio (OR) was reported by logistic regression. The results demonstrated that a side step of the ball-carrier reduced the risk of concussion for tacklers (OR=0.13 [95% CI, 0.03-0.58]; P=.008). Conversely, the tackler's head/neck contacting the ball-carrier (OR=18.62 [95% CI, 4.59-75.49]; P<.001) and not remaining bound to the ball-carrier since making initial contact (OR=4.38 [95% CI, 1.69-11.34]; P=.002) were identified as risk factors for the concussion of tacklers. These results suggest that avoidance movements of the ball-carrier prior to tackling reduced the risk of concussion and that incorrect tackling techniques contributed to an increased occurrence of concussion. Furthermore, the probability of concussion for tacklers increased when their head was in front or to one side of the ball-carrier, and the direction of the tackle also affected the risk of concussion, especially from the side. Therefore, it is important to emphasize the tackler's head position in conjunction with the direction of tackle.