Cause Of Concussion Research Articles

Cause of Concussion With Persisting Symptoms Is Associated With Long-Term Recovery and Symptom Type, Duration, and Number in a Longitudinal Cohort of 600 Patients.

It is important for patients and clinicians to know the potential for recovery from concussion as soon as possible after injury, especially in patients who do not recover completely in the first month and have concussion with persisting concussion symptoms (C+PCS). We assessed the association between the causes of concussion and recovery from C+PCS in a consecutive retrospective and prospective cohort of 600 patients referred to the Canadian Concussion Center (CCC) at Toronto Western Hospital. Data were obtained from clinical records and follow-up questionnaires and not from a standardized database. A novel method was used to assess long-term recovery, and multi-variable Cox proportional hazards models were used to assess relationships between cause of concussion and time to recovery. We examined the subsequent recovery of patients who had not recovered after at least one month from the time of concussion. Patients were grouped into the following four causes: sports and recreation (S&R, n = 312, 52%); motor vehicle collisions (MVC, n = 103, 17%); falls (n = 100, 17%); and being struck by an object including violence (SBOV, n = 85, 14%). The MVC group had the highest percentage of females (75.7%), the oldest participants (median: 40.0 [interquartile range (IQR):30.5-49.0] years), the most symptoms (median:11.0 [IQR:8.5-15.0]), and the longest symptom duration (median: 28.0 [IQR:12.0-56.00] months). In contrast, the S&R group had the highest percentage of males (58.1%), the youngest participants (median:20.0 [IQR:17.0-30.0] years), the best recovery outcome, and shortest symptom duration (median:22.0 [IQR:8.0-49.5] months). Significant differences among the four causes included age (p < 0.001), sex (p < 0.001), number of previous concussions (p < 0.001), history of psychiatric disorders (p = 0.002), and migraine (p = 0.001). Recovery from concussion was categorized into three groups: (1) Complete Recovery occurred in only 60 (10%) patients with median time 8.0 (IQR:3.5-18.0) months and included 42 S&R, 7 MVC, 8 falls, and 3 SBOV; (2) Incomplete Recovery occurred in 408 (68.0%) patients with persisting median symptom time of 5.0 (IQR:2.0-12.0) months; and (3) Unknown Recovery occurred in 132 (22.0%) patients and was because of lack of follow-up. In summary, the cause of C+PCS was associated with the type, number, and duration of symptoms and time required for recovery, although all causes of C+PCS produced prolonged symptoms in a large percentage of patients, which emphasizes the importance of concussions as a public health concern necessitating improved prevention and treatment strategies.

Concussion Rates in Youth Lacrosse Players and Comparison With Youth American Football.

There has been little focus on concussions in youth lacrosse players in the United States. To provide a descriptive analysis of the epidemiology and incidence of concussions in youth lacrosse and compare the results with well-documented analyses of concussions in youth American football. Descriptive epidemiology study. Data on concussions in pediatric patients playing lacrosse from 2006 to 2019 were collected using the National Electronic Injury Surveillance System (NEISS). Weighted calculations and combined participation data obtained from membership in USA Lacrosse were used to estimate injury incidence. A comparison dataset was created using the NEISS data on youth football-related concussions. The cause of concussion was categorized into player-to-player, player-to-stick, player-to-ball, or player-to-ground contact. A total of 37,974 concussion injuries related to lacrosse were identified in players with a mean age of 14.5 ± 3.5 years; 70% of concussions occurred in boys. National participation in lacrosse increased from 2006 to 2011 by a mean of 10.3% annually, followed by a lower annual growth rate of 2.5% from 2012 to 2019. The overall incidence of concussion injuries increased over the study period (r = 0.314), with the incidence rate in boys being greater than that of girls from 2009 to 2013. The most common cause of concussion was player-to-ground contact for boys and player-to-ball or player-to-stick contact for girls. The mean annual concussion incidences in youth lacrosse and youth football were 443 and 355 per 100,000 participants, respectively. Over the study period, 16% of lacrosse injuries were diagnosed as concussions, a higher mean annual incidence per 100,000 participants than that of youth football (443 vs 355). The cause of concussion was different based on sex, with higher rates of player-to-ball or player-to-stick contact in female players versus player-to-ground contact in male players.

Tackling the tackle 1: A descriptive analysis of 14,679 tackles and risk factors for high tackles in a community-level male amateur rugby union competition during a lowered tackle height law variation trial

ObjectivesIn rugby union (rugby), the tackle is the most frequent cause of concussion and thus a target for intervention to reduce concussion incidence. The aim of this study is to describe tackle characteristics and factors associated with illegal high tackles in amateur community-level rugby during a lowered (armpit level) tackle height law variation trial. DesignProspective observational cohort study. MethodsVideo surveillance of a single season, four-league competition with coding of video data according to a predefined coding framework. Descriptive statistics of tackle detail and logistic regression was performed to analyse factors associated with high tackles. ResultsOne hundred and eight matches with 14,679 tackles and a mean of 137 (±30) tackles per match were analysed. High tackles (above armpit level) had significantly greater odds of occurring in the lower (2nd–4th) leagues (OR: 1.95; 95 % CI: 1.6–2.4; p < 0.001), front-on tackles (OR: 1.61; 95 % CI: 1.3–2.0; p < 0.001), arm tackles (OR: 1.65; 95 % CI: 1.3–2.1; p < 0.001), bent-at-waist ball carrier (OR: 1.93; 95 % CI: 1.6–2.4; p < 0.001), falling/diving ball carrier (OR: 2.21; 95 % CI: 1.6–3.1; p < 0.001), and an upright tackler (OR: 3.38; 95 % CI: 2.7–4.2; p < 0.001). A falling/diving tackler had significantly lower odds of being associated with a high tackle (OR: 0.44; 95 % CI: 0.3–0.6; p < 0.001). ConclusionsOverall mean tackles per match were similar to those of senior amateur and elite rugby. League, tackle type, tackle aspect, and player body positions were associated with high tackles. These findings reiterate the need for ongoing efforts to identify and implement mitigating strategies to reduce tackle-related injury risk.

Role of sex and gender in concussion outcome differences among patients presenting to the emergency department: a systematic review

ObjectiveThis systematic review aimed to identify research involving adults presenting to the emergency department (ED) with a concussion to document the reporting of sex and/or gender according to the Canadian...

A-66 Clinical Neuropsychology Journal Articles about Concussion from 2010-2020

Abstract Purpose Concussions are a major public health concern and are caused by falls, motor vehicle accidents, sports-related injuries, and assaults. Concussion research increased dramatically in recent decades, with 1,015 articles about concussion listed in PubMed in 2020, up from 30 in 2000. The focus of concussion research is evolving from assessment tools towards education, biomarkers, and intervention. Little is known about the topics of concussion research in clinical neuropsychology, but this knowledge might direct research efforts in the future. Data Selection We coded the content of titles of concussion articles published in 12 clinical neuropsychological journals from 2010-2020. This project is part of a study about the cultural and multicultural content of clinical neuropsychology articles. From this larger dataset, titles that included the terms concussion, sub-concussive, mild traumatic brain injury were collected (n=317). Data Synthesis Content in titles for concussions articles were, in order, sports (29.0%), children/adolescents (23.3%), emotion and personality issues (23.0%), post-concussive symptoms (12.9%), psychiatric symptoms (12.9%), military (15.8%), sex differences (2.5%), multiple concussions (2.5%), cultural or multicultural neuropsychology (2.2%), and older adults (1.3%). Conclusions Clinical neuropsychology research is proportionately over-focused on sports concussion to the exclusion of other causes of concussion. That said, sports concussion is easier to study than other causes of concussion and thus, this work has tremendous value for the field. Concussion research would best serve public health by focusing more on sex differences, multicultural issues, and other individual difference factors that alter risk for and recovery from concussion.

Epidemiological analysis of pediatric baseball and softball concussions in United States emergency departments

PurposeTo evaluate the epidemiology of concussions in pediatric baseball and softball players. We hypothesized that head-to-ball injuries would be the most common cause of concussions. MethodsThe National Electronic Injury Surveillance System (NEISS) database was used to gather data. Concussions occurring during baseball and softball participation in pediatric patients (4–17 years old) from 2012 to 2021 was gathered. Concussion mechanisms were grouped into 5 categories: head-to-player, head-to-ball, head-to-surface (ground, walls, railings), head-to-bat, and unknown. Linear regression models were used to assess changes in yearly concussion rates over the study period. Results from these models were reported using parameter estimates and the estimated Pearson correlation coefficient. ResultsA weighted total of 54,978 baseball and softball related concussion injuries were analyzed. The average weighted age of our cohort at the time of injury was 13.1 years, with 54.1% (n = 29,761) of concussions occurring in males. The national estimated incidence of concussion injuries decreased non-significantly over the study period (slope estimate = −311 concussions/year, r = −0.625, p-value = 0.054). The majority of weighted national estimate concussions were due to head-to-ball injuries (n = 34,650; 63.0%), followed by head-to-player (n = 8501; 15.5%), head-to-surface (n = 5347; 9.7%), and head-to-bat (n = 5089; 9.3%). On sub-analysis, individuals were grouped into 3 age brackets: 4–8, 9–13, and 14–17 years. The most common mechanism of concussions in children of all ages was head-to-ball. The incidence of head-to-player and head-to-surface injuries increased throughout each age group, while head-to-bat decreased. ConclusionThe incidence of concussions in pediatric baseball and softball athletes has been decreasing non-significantly over our 10-year study period. The most common mechanism of concussions in our study was head-to-ball injuries.

Concussion in professional wrestling: agency, structure and cultural change

ABSTRACT In this article, we utilise the social dynamics of concussion in professional wrestling to examine and critique calls for cultural change as a solution to the crisis of concussion in sport. Drawing on interview data from wrestlers, promoters, referees and healthcare providers in UK professional wrestling, we illustrate the experiences, attitudes and subcultural norms exhibited in relation to concussion. Despite increasing concerns that brain injuries present unique risks to long-term health, wrestlers continue to embody a culture in which pain is ignored, and ‘playing’ with brain injury is linked to notions of masculinity and wrestling identity. We further explore the organisational features of wrestling, which facilitate and compound these risk-taking behaviours, and conclude by identifying the structural-cultural causes of concussion in wrestling. In sum, economic precarity encouraged risk-taking behaviours, while the ‘free agent’ status of many wrestlers obviated the potential for any continuity of healthcare or paternalistic protection. Moreover, changes to the dominant performative character of wrestling led many to undertake increasingly risky moves, and the serial nature of character development and the centrality of interpersonal negotiations in workplace practice threw precautionary attitudes into conflict with self-identity and social reputational concerns. We therefore conclude that existing public health interventions designed to address concussion in sport, and particularly the concept of cultural change, need to diversify from predominantly medical and psychology-based models and embrace more holistic, structural conceptions of culture.

Concussion vs. resignation by submission: Technical-tactical behavior analysis considering injury in mixed martial arts.

This research study verified the technical–tactical actions during the mixed martial arts (MMA) fights to generate serious enough injury to stop the MMA round, determining technical-tactical potential risk factors for injury in official MMA combats, according to Concussion or Resignation per Submission. A total of 990 rounds with concussions and 627 resignations per submission were considered with severe injury (i.e., a fight ended by a doctor or referee). All injuries were diagnosed and managed by attending ringside physicians during the MMA fights and rounds and had a continuous technical–tactical behavior analysis, p ≤ 0.05. The leading cause of concussion was due to head trauma (~90%), with higher dependence on head strikes scored actions. Comparisons between Concussion and Resignation per Submission combats demonstrated differences between distance head strikes actions [13(6,25) vs. 9(4,18) frequencies], clinch head strikes actions [1(0;4) vs. 1(0;3) frequencies], ground head strikes actions [1(0;8) vs. 2(0;10) frequencies] and takedowns actions [0(0;1) vs. 1(0;2) frequencies]. This information may provide significant evidence regarding the doctor stoppage in concussion combats and when it could be called by officials supervising MMA.

Sex and gender differences in mild traumatic brain injury/concussion.

The high incidence of concussions/mild traumatic brain injury and the significant number of people with persisting concussion symptoms as well as the concern for delayed, neurodegenerative effects of concussions makes them a major public health concern. There is much to learn on concussions with respect to pathophysiology as well as vulnerability and resiliency factors. The heterogeneity in outcome after a concussion warrants a more personalized approach to better understand the biological and psychosocial factors that may affect outcome. In this chapter we address biological sex and gender as they impact different aspects of concussion including incidence, risk factors and outcome. As well, this chapter will provide a more fulsome overview of intimate partner violence, an often-overlooked cause of concussion in women. Applying the sex and gender lens to concussion/mild traumatic brain injury is imperative for discovery of its pathophysiology and moving closer to treatments.

Determining the Differences in Acute Phase of Astrocytic Activation Between Male and Female Rats – A Research Protocol

Introduction: Primary blast injuries are a common cause of mild traumatic brain injury (mTBI) and are the leading cause of both closed and open-skull brain injuries. Following mTBI, astrocytic activation and reactive gliosis occur which results in an upregulation of various astrocytic markers such as glial fibrillary acidic protein (GFAP). These markers can act as biomarkers for patients with mTBI. This protocol will examine how primary blast injury affects the acute phase of astrocytic activation in male and female rats. Rationale: This experiment will determine the sex differences in astrocytic activation after male and female rodent mTBI to replicate the effects of primary blast injury resulting from improvised explosive device (IED) impact in humans. These injuries are the most common cause of concussions in deployed military personnel. Understanding sex differences in the extent of astrocytic activation and the time window between blast impact and initial activation will have implications for trauma treatment in the field to prevent excessive neurodegeneration. There is also a lack of research on the sex-specific acute astrocytic activation resulting from blast injuries. Methods: Adult male and female wild-type Sprague Dawley rats will be randomly assigned to (a) male sham, (b) female sham, (c) male mTBI, or (d) female mTBI group. After each rat is exposed to the primary blast injury, coronal sections of the brains will be collected. Flow cytometry and quantitative polymerase chain reaction (qPCR) will be used to analyze astrocytic gene expression. Expected Results: For the 48-hour duration following primary blast injuries, GFAP levels are expected to increase to different extents for both males and females. We expect this difference between males and females to occur due to hormonal suppression of astrogliosis in females. Discussion: The analysis of astrocytic activation among female and male rats caused by closed skull blast-specific injury will help to determine sex-specific treatments and therapeutic applications for injured military soldiers. Conclusion: This study will allow for a greater understanding of sex differences in astrocytic activation, which may benefit treatment plans for mTBI patients.

Association between post-concussion symptoms and oculomotor deficits among adolescents

ABSTRACT Purpose To examine the association between Post-Concussion Symptom Scale (PCSS) scores, Convergence Insufficiency Symptom Survey (CISS) scores, and oculomotor deficits post-concussion. Methods Records of adolescent patients examined in a multidisciplinary concussion clinic between July 2014 and May 2019 were reviewed. PCSS and CISS scores, results of eye examination and oculomotor assessment, concussion history, and demographics were abstracted. Results One hundred and forty patient records (median age, 15.3 years; 52 males, presented 109 days (median) from their most recent concussion) met inclusion criteria. Mean total scores on PCSS and CISS were 46.67 ± 25.89 and 27.13 ± 13.22, respectively, and were moderately correlated with each other (r = 0.53, p < .001). Oculomotor deficits were observed in 123 (88%) patients. Step-wise linear regression identified increased PCSS total score to be significantly associated with decreased amplitude of accommodation (p < .001). Increased CISS total score was significantly associated with receded near point of convergence, developmental eye movement test error scores, and cause of concussion. Conclusion High PCSS scores may indicate an accommodation deficit and thus prompt an oculomotor assessment in patients following a concussion. Using the CISS and a detailed oculomotor assessment may reveal underlying oculomotor deficits, which may benefit from treatment.

Impact Performance Comparison of Advanced Snow Sport Helmets with Dedicated Rotation-Damping Systems

Rotational acceleration of the head is a principal cause of concussion and traumatic brain injury. Several rotation-damping systems for helmets have been introduced to better protect the brain from rotational forces. But these systems have not been evaluated in snow sport helmets. This study investigated two snow sport helmets with different rotation-damping systems, termed MIPS and WaveCel, in comparison to a standard snow sport helmet without a rotation-damping system. Impact performance was evaluated by vertical drops of a helmeted Hybrid III head and neck onto an oblique anvil. Six impact conditions were tested, comprising two impact speeds of 4.8 and 6.2 m/s, and three impact locations. Helmet performance was quantified in terms of the linear and rotational kinematics, and the predicted probability of concussion. Both rotation-damping systems significantly reduced rotational acceleration under all six impact conditions compared to the standard helmet, but their effect on linear acceleration was less consistent. The highest probability of concussion for the standard helmet was 89%, while helmets with MIPS and WaveCel systems exhibited a maximal probability of concussion of 67 and 7%, respectively. In conclusion, rotation-damping systems of advanced snow sport helmets can significantly reduce rotational head acceleration and the associated concussion risk.

Video analysis of concussion mechanisms and immediate management in French men's professional football (soccer) from 2015 to 2019.

In this study, the concussion mechanisms were analyzed in male professional competition football, with the main objective to specify the frequency of head-to-head impact, and immediate management of the concussed players was described in order to check its compliance with the recommendations of football's governing bodies. Based on continuously recorded data from the French Football Federation (FFF), a retrospective database of all reported concussions during matches in the 1st and 2nd French Male leagues was generated comprising seasons 2015/16-2018/19. Injury mechanisms, playing action, immediate medical assessment and management of concussed players, and foul play-referee's decision, were analyzed from video recordings. In total, 41 concussions were reported (incidence rate of 0.44/1000 hours of match exposure [95% CI: 0.40 to 0.49]) of which 36 were identified and analyzed on video sequences. The commonest playing action leading to concussion was aerial challenge (61%), and the main mechanism was head-to-head impact (47%). Following the head impact, 28% of concussed players were not medically assessed on pitch and 53% returned to play the same match. Head-to-head impact was not associated with systematic medical assessment, nor with foul play. In conclusion, the main cause of concussions involved head-to-head impact occurring when two players challenge for heading the ball in the air. The detection of potential concussive head impacts and the immediate management of players possibly concussed during matches remain insufficient according to the international recommendations. Some rules changes, with particular vigilance in case of head-to-head impact, should be discussed.

Concussions in Soccer: An Epidemiological Analysis in the Pediatric Population.

Background:As the popularity of youth soccer has increased in the United States, more attention has been focused on the effect of concussion injuries, with recent debate on whether heading should be disallowed. There is little evidence examining the epidemiology of these injuries.Purpose/Hypothesis:The purpose of this study was to examine the prevalence and incidence of youth soccer-related concussions. We hypothesized that concussion rates will correlate with increased participation in youth soccer.Study Design:Descriptive epidemiology study.Methods:The National Electronic Injury Surveillance System was used to collect data on concussion injuries that occurred during soccer in pediatric patients from 2008 through 2016. Soccer-related concussion injuries were identified using specific codes and were analyzed for variation in disposition. The types of contact were categorized into player-to-player, head-to-ball, player-to-post, and player-to-ground contacts. Contact types related to hospitalization were subanalyzed.Results:A weighted total of 3285 concussion injuries were identified during the study period, with an average of 386 concussions each year. The average age was 13.5 years, and there were no differences seen in incidence between the sexes. The overall incidence of concussion injuries increased (r = 0.789), while hospitalizations decreased (r = –0.574). The most common cause of concussion was found to be player-to-player contact, followed by head-to-ground contact and then head-to-ball contact. Subanalysis showed that 13% of hospitalizations were due to head-to-ball contact, compared with 39% and 44% due to player-to-player contact and head-to-ground contact, respectively. The relative risk of hospitalization from a concussion due to head-to-ball contact was 7.06 compared with 22.60 due to head-to-ground contact.Conclusion:The incidence of concussion in youth soccer has been increasing over the past decade as predicted, given the growing participation rates in both male and female soccer players. The most common cause of concussion was player-to-player contact, and the majority of concussions resulting in hospitalization occurred because of head-to-ground contact.

Neuroanatomy and Imaging Assessment in Traumatic Brain Injury

ABSTRACT Concussion is a common injury in childhood with an estimated 1.4 million children sustaining concussions annually in the United States. While many concussions occur in the sports and recreation setting, it is important to recognize that non-sports and recreation activities are also common causes of concussion in childhood. Since neurologic projections associated with the afferent and efferent visual system are widely distributed throughout the brain and thought to comprise over 50% of brain function, it is not surprising that the diffuse sear injury associated with concussion often produces visual dysfunction. This review will concentrate on the efferent visual motor pathways that may be affected in concussion.

Epidemiologic Assessment of Concussions in an NCAA Division I Women's Soccer Team.

Background:Among collegiate sports, ice hockey and wrestling have been reported to have the highest rates of concussion injury. Recent literature has shown that among all sports, female soccer players had the highest rate of concussion injury at the high school level. Sport-specific analysis will increase our knowledge of epidemiologic characteristics of this serious injury in young soccer players, where “heading” is commonly involved during participation.Hypothesis:Heading during soccer will be associated with increased frequency of concussion injury in collegiate female players compared with other mechanisms of injury, and concussion injury mechanism and rates will differ by setting of injury (practice or match) and player position.Study Design:Descriptive epidemiologic study.Methods:This was a retrospective review and epidemiologic analysis of all concussions documented from a single National Collegiate Athletic Association (NCAA) Division I female collegiate soccer team between 2004 and 2017. A total of 381 participants were reviewed, and concussion injury mechanism, setting (practice or match), player position, and number of games and practices missed due to injury were analyzed.Results:Overall, 25 concussions in 22 players from the 2004 to 2017 seasons were identified, for an annual rate of 1.79 concussions per year. Collisions (36%) followed by headers (20%) were the most common mechanisms. Forwards sustained the most concussions (32%). Injuries were more common in games (56%) than practice (40%). Of note, the most common cause of concussion during practice was headers (40%). Of the concussions documented, 20 (91%) were the player’s first concussion. On average, each concussion resulted in a player missing 3.96 games and 12.46 practices.Conclusion:Our results demonstrate that concussion rates in female NCAA soccer players vary by position and occur with different frequencies and mechanisms in practice and games. Interventions for concussion avoidance should aim to limit exposure to high-risk activity, including player-to-player contact in games and headers in practice. Although gameplay and collisions can be unpredictable and difficult to control, practice settings can be modified in an attempt to decrease risk.

A Perspective From the Middle East on the Topic of Concussion

Background: Concussion is the most prevalent form of traumatic brain injury. Western countries debate it as a public health issue. Middle Eastern (ME) countries lag behind with a concussion incidence surveillance of 25% that of European countries. &#x0D; &#x0D; Objective: The purpose of our study was to review concussion resulting from traumatic brain or sports injuries in civilian nationals of the ME.&#x0D; &#x0D; Methods: We carried out PubMed literature search of all related articles in the past thirty years using search terms reflecting concussion and sports injuries in ME countries of Bahrain, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Palestine, Qatar, Saudi Arabia, Syria, Turkey, United Arab Emirates, and Yemen. &#x0D; &#x0D; Results: 72 articles met our search criteria with relatively little data found on concussion within the parameters of this review. However, the reports that were found were diverse. Israel, Turkey and Iran led in publications. Motor vehicle accidents were the leading cause of concussion from TBI (50-57%) followed by domestic injuries (30-40%) and sports injuries at 4-7%. Extremity injuries were most commonly reported unlike head injuries often invisible and underreported. Male gender, young children, pedestrian and car traffic accidents, lack of protective gear, cell phone use, impulsive behaviors as well as training overload, lack of sleep, contact sports and violence were all risk factors for concussion. &#x0D; &#x0D; Conclusions: In this review, we highlighted the nascent topic of concussion in the ME and the need for additional research dictating awareness programs and implementing new safety policies to lower morbidity and mortality across all ages.

Parametric study of impact parameters on peak head acceleration and strain for collision impacts in sport

Collisions are a common cause of concussions. The nature of a collision impact is governed by the velocity of the striking players and the body parts involved. The purpose of this study was to describe the effects of velocity, mass, surface stiffness and location on peak linear and angular acceleration and strain.A variable-mass pendulum fitted with simplified impact surfaces representing the stiffness of an unprotected head, a protected (helmet) and a well-padded (i.e. shoulder pad) condition were used to impact a Hybrid III headform at four locations and velocities. Headform accelerations were input into a finite-element model to approximate peak strain in the cerebrum.Stiffness was most influential on peak linear and angular acceleration, and strain was most influenced by velocity. Interaction effects demonstrated that the 9 kg mass had consistently higher peak linear and angular acceleration and strain than the 15 kg mass between 3.0 and 4.5 m/s. Mass and velocity interactions may have important implications for age and size related concussion risk.

Interaction of external head impact parameters on region and volume of strain for collisions in sport

Collisions with the head are the primary cause of concussion in contact sports. Head impacts can be further characterized by velocity, striking mass, compliance, and location (direction). The purpose of this study was to describe the interaction effects of these parameters on peak strain in four brain regions and the volume of strain for collision impacts. A pendulum test set-up was used to deliver impacts to an adult Hybrid III headform according to four levels of mass (3, 9, 15, and 21 kg), four velocities (1.5, 3.0, 4.5, and 6.0 m/s), two impact locations (through the centre of gravity and a non-centre of gravity), and three levels of compliance simulating unprotected, helmeted, and well-padded conditions in sport. Headform accelerations were input into a brain finite element model to obtain peak strain in the frontal, temporal, parietal, and occipital lobes and the volume of the brain experiencing 0.10, 0.15, 0.20, and 0.25 strains. Centre-of-gravity impacts created the highest strains (peak and volume) under low compliance and non-centre-of-gravity impacts produced greater strain responses under medium and high compliance conditions. The temporal lobe was the region that consistently displayed the highest peak strains, which may be due to the proximity of the impact locations to this region. Interactions between mass and velocity displayed effects where the 9-kg mass had higher peak and volumes of strain than the 15-kg mass at velocities of 3.0 and 4.5 m/s. This study demonstrates the important role of interacting impact parameters on increasing strain responses that are relevant to the spectrum of diffuse brain injuries, including concussion.

Preventing Concussions From Foul Tips and Backswings in Professional Baseball: Catchers' Perceptions of and Experiences With Conventional and Hockey-Style Masks.

To understand catchers' preferences for mask type and perceptions regarding safety, comfort, and fit, and determine whether mask type is correlated with self-reported concussion and related symptoms after impacts from foul tips or backswings. Cross-sectional study. Survey of active baseball catchers. Professional baseball catchers. From May 1, 2015, to June 30, 2015, an online survey was administered in English and Spanish to all Major and Minor League catchers (n = 836). Survey items addressed the type of mask routinely and previously used (conventional or hockey style); brand and material (steel or titanium); perceptions regarding safety, comfort, and fit; and experiences with concussions. The sample consisted of 596 catchers of which 26% reported being diagnosed with a concussion. Some concussions occurred from non-baseball activities, such as car accidents or off the field incidents. For those that occurred playing baseball, 35% resulted from a foul tip. Once catchers entered professional baseball, the use of a conventional mask rose significantly: 71% of catchers reported wearing conventional-style masks, and 30% hockey-style masks at the time the survey was conducted (P < 0.05). Both conventional and hockey-style mask wearers significantly selected hockey-style masks as providing better overall safety and protection than conventional masks (P < 0.05). This research supports foul tips as an important cause of concussion in catchers and provides important information about preferences among catchers for masks that are not perceived as the safest and strongest. Future research should supplement these data by conducting laboratory testing to determine which masks are stronger and by collecting qualitative data to explore why some players are more likely to wear a mask type that they perceive as offering less safety or protection.