Epidemiology of Sport-Related Concussions in High School Athletes: National Athletic Treatment, Injury and Outcomes Network (NATION), 2011-2012 Through 2013-2014

Secondary School State Athletic Association Health and Safety Policy Development Processes

BACKGROUND

The National Federation of State High School Associations provides recommendations regarding health and safety policies; however, policy development is governed at the state level. Given interstate differences in governance, the primary purpose was to describe processes that State High School Athletic Associations (SHSAAs) utilize to develop a new policy. The secondary objective was to determine what methods associations use to implement new policies.

METHODS

A cross-sectional survey requested SHSAA (n = 51) representatives to report how athlete health and safety policies are introduced, revised, approved, and implemented within their state. The 22-question survey was developed to gather variables for the aims of the study. Descriptive statistics were calculated for each survey item.

RESULTS

Of states who responded (n = 33), most reported a 2-committee (n = 24, 72.7%) process for developing and vetting policies, with initiation from the Sports Medicine Advisory Committee (n = 27, 81.8%), followed by an executive-level committee (n = 18, 66.7%). States reported total time from policy initiation to final approval ranged from 2 weeks to over 12 months. When a new policy was approved, most states indicated implementation began with an e-mail (n = 24, 72.7%) sent to Athletic Directors (n = 26, 78.8%). School principal or district superintendent were reported as the position in charge of compliance (36.4%, n = 12).

CONCLUSIONS

Most SHSAAs use a 2-step process to write and review an athlete health and safety policy before approval. SHSAAs that require a longer policy development time could delay the implementation of important health measures. SHSAAs could consider additional communication methods to ensure information reaches all stakeholders.

Biofidelity and Limitations of Instrumented Mouthguard Systems for Assessment of Rigid Body Head Kinematics

Instrumented mouthguard systems (iMGs) are commonly used to study rigid body head kinematics across a variety of athletic environments. Previous work has found good fidelity for iMGs rigidly fixed to anthropomorphic test device (ATD) headforms when compared to reference systems, but few validation studies have focused on iMG performance in human cadaver heads. Here, we examine the performance of two boil-and-bite style iMGs in helmeted cadaver heads. Three unembalmed human cadaver heads were fitted with two instrumented boil-and-bite mouthguards [Prevent Biometrics and Diversified Technical Systems (DTS)] per manufacturer instructions. Reference sensors were rigidly fixed to each specimen. Specimens were fitted with a Riddell SpeedFlex American football helmet and impacted with a rigid impactor at three velocities and locations. All impact kinematics were compared at the head center of gravity. The Prevent iMG performed comparably to the reference system up to ~ 60 g in linear acceleration, but overall had poor correlation (CCC = 0.39). Prevent iMG angular velocity and BrIC generally well correlated with the reference, while underestimating HIC and overestimating HIC duration. The DTS iMG consistently overestimated the reference across all measures, with linear acceleration error ranging from 10 to 66%, and angular acceleration errors greater than 300%. Neither iMG demonstrated consistent agreement with the reference system. While iMG validation efforts have utilized ATD testing, this study highlights the need for cadaver testing and validation of devices intended for use in-vivo, particularly when considering realistic (non-idealized) sensor-skull coupling, when accounting for interactions with the mandible and when subject-specific anatomy may affect device performance.

The Association Among Clinical Profiles, Modifiers, and Prolonged Recovery in Adolescents With Sport-Related Concussion

OBJECTIVE

The purposes were to (1) describe the prevalence of clinical profiles and modifiers, (2) examine the association between clinical profiles and prolonged recovery, and (3) examine the interaction between clinical profiles and modifiers and prolonged recovery in adolescents with sport-related concussion (SRC).

DESIGN

Retrospective, cross-sectional.

SETTING

Interdisciplinary specialty sports concussion clinic.

PATIENTS

Patients (n = 299) aged 12 to 19 years who were diagnosed with SRC within 30 days of injury.

INDEPENDENT VARIABLES

Clinical profiles and modifiers were decided by the clinical judgment of the clinical neuropsychologist and sports medicine physician, using data from the Clinical Profile Screen and information gathered from the clinical interview, neurocognitive, and vestibular and ocular motor testing.

MAIN OUTCOME MEASURES

Prolonged recovery was defined as ≥28 days from the date of injury to the date of clearance.

RESULTS

The most common clinical profiles were migraine (34.8%) and cognitive-fatigue (23.4%). There were no significant relationships between clinical profiles and prolonged recovery (Wald = 5.89, df = 4, P = 0.21). The presence of a modifier did not significantly affect the relationship between clinical profiles and prolonged recovery ( = 6.5, df = 5, P = 0.26). The presence of any modifier yielded a 10-day increase in median recovery time within the cognitive/fatigue clinical profile (Wilcoxon rank-sum = 268.5, P = 0.01).

CONCLUSIONS

Although patients with a clinical profile and modifier may not experience prolonged recovery, they may experience longer recovery time than patients with a clinical profile and no modifier.

Overview of Treatment Options for Mild Traumatic Brain Injury: A Literature Review

The incidence and prevalence of concussion, a type of mild traumatic brain injury (mTBI), have steadily increased among athletes, both students and professionals, across a wide variety of sports, including, but not limited to, swimming, tennis, football, and boxing. Recent data have demonstrated that sports are one of the leading causes of concussions among student athletes. While the exact mechanism of concussion onset has yet to be fully elucidated, data suggest that the pathophysiology involves rotational acceleration and deceleration of the brain, leading to axon tearing and disturbance in the metabolic cascade of glucose. Concussive events can have debilitating effects on an athlete, including chronic traumatic encephalopathy (gradual degeneration of brain tissue) that is related to personality changes, emotional disorders, and even dementia. Common symptoms associated with concussion include dizziness, nausea, vomiting, and headaches. The physical assessment consists of a combination of tools involving the mental status examination, vital signs, cervical spine exam, eye exam, and neurological testing. The use of osteopathic manipulative medicine (OMM), pharmacotherapy, hyperbaric oxygen therapy (HBOT), aerobic exercise, balance, and/or vestibular therapy are many common treatment approaches for concussion and post-concussion sequelae. This literature review aims to provide insight into concussions, the current treatment options available, and the new developments in concussions per the Amsterdam 2022 International Consensus Statement on Concussion in Sport published in 2023.

ENIGMA's simple seven: Recommendations to enhance the reproducibility of resting-state fMRI in traumatic brain injury

Resting state functional magnetic resonance imaging (rsfMRI) provides researchers and clinicians with a powerful tool to examine functional connectivity across large-scale brain networks, with ever-increasing applications to the study of neurological disorders, such as traumatic brain injury (TBI). While rsfMRI holds unparalleled promise in systems neurosciences, its acquisition and analytical methodology across research groups is variable, resulting in a literature that is challenging to integrate and interpret. The focus of this narrative review is to address the primary methodological issues including investigator decision points in the application of rsfMRI to study the consequences of TBI. As part of the ENIGMA Brain Injury working group, we have collaborated to identify a minimum set of recommendations that are designed to produce results that are reliable, harmonizable, and reproducible for the TBI imaging research community. Part one of this review provides the results of a literature search of current rsfMRI studies of TBI, highlighting key design considerations and data processing pipelines. Part two outlines seven data acquisition, processing, and analysis recommendations with the goal of maximizing study reliability and between-site comparability, while preserving investigator autonomy. Part three summarizes new directions and opportunities for future rsfMRI studies in TBI patients. The goal is to galvanize the TBI community to gain consensus for a set of rigorous and reproducible methods, and to increase analytical transparency and data sharing to address the reproducibility crisis in the field.

Optimizing Concussion Care Seeking: Connecting Care-Seeking Behaviors and Neurophysiological States Through Blood Biomarkers

BACKGROUND

Timely and appropriate medical care after concussion presents a difficult public health problem. Concussion identification and treatment rely heavily on self-report, but more than half of concussions go unreported or are reported after a delay. If incomplete self-report increases exposure to harm, blood biomarkers may objectively indicate this neurobiological dysfunction.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare postconcussion biomarker levels between individuals with different previous concussion diagnosis statuses and care-seeking statuses. It was hypothesized that individuals with undiagnosed concussions and poorer care seeking would show altered biomarker profiles.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Blood samples were collected from 287 military academy cadets and collegiate athletes diagnosed with concussion in the Advanced Research Core of the Concussion Assessment, Research and Education Consortium. The authors extracted each participant's self-reported previous concussion diagnosis status (no history, all diagnosed, ≥1 undiagnosed) and whether they had delayed or immediate symptom onset, symptom reporting, and removal from activity after the incident concussion. The authors compared the following blood biomarkers associated with neural injury between previous concussion diagnosis status groups and care-seeking groups: glial fibrillary acidic protein, ubiquitin c-terminal hydrolase-L1 (UCH-L1), neurofilament light chain (NF-L), and tau protein, captured at baseline, 24 to 48 hours, asymptomatic, and 7 days after unrestricted return to activity using tests of parallel profiles.

RESULTS

The undiagnosed previous concussion group (n = 21) had higher levels of NF-L at 24- to 48-hour and asymptomatic time points relative to all diagnosed (n = 72) or no previous concussion (n = 194) groups. For those with delayed removal from activity (n = 127), UCH-L1 was lower at 7 days after return to activity than that for athletes immediately removed from activity (n = 131). No other biomarker differences were observed.

CONCLUSION

Individuals with previous undiagnosed concussions or delayed removal from activity showed some different biomarker levels after concussion and after clinical recovery, despite a lack of baseline differences. This may indicate that poorer care seeking can create neurobiological differences in the concussed brain.

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

Background

There has been little focus on concussions in youth lacrosse players in the United States.

Purpose

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.

Study Design

Descriptive epidemiology study.

Methods

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.

Results

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.

Conclusion

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.

Concussions: A Review of Physiological Changes and Long-Term Sequelae

A concussion is a type of mild traumatic brain injury (mTBI). It is prevalent among athletes across a wide variety of sports. The exact mechanism of a concussion is unknown, but it is currently accepted that the acceleration and deceleration of the brain is the insult causing disturbances in activity. The most common symptoms of concussions include but are not limited to dizziness, nausea, vomiting, and headaches. With repetitive concussive injuries, athletes can experience permanent changes such as chronic traumatic encephalopathy (gradual degeneration of brain tissue), which can lead to personality changes and memory deficits. This literature review aims to provide insight into concussions and the evaluation of physiological changes and long-term sequelae. A comprehensive literature search was performed from April 2012 to April 2022 using PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online) and Embase databases. Nineteen articles were finally included in the literature review. The review shows that neuroimaging results demonstrated significant changes in the brain structure and function including alternations in the thalamus, hippocampus, corpus callosum, and the white matter, which can extend beyond the symptom amelioration. In addition, other approaches include brain metabolism, cerebral blood flow, and glucose utilization. Additional techniques include the evaluation of fatigue levels and the alterations in biomarkers, specifically IL-6. These approaches have demonstrated that consequences of concussions, including alternations in brain structure and function, can extend beyond an athlete's report of symptom resolution, and should be taken into consideration for return to play. The physiological changes present after a concussion have the potential to develop into long-term complications such as academic difficulty, cognitive decline, gut microbiome changes, gait changes, and increased risk of lower extremity injury. The findings in the literature review determine that is important to immediately address the symptoms of concussions to expedite treatment and prevent deleterious changes to the brain.

Common Injuries in Female Competitive Softball Players

The popularity of softball is rising among female athletes with more than two million players between the ages of 12 and 18 competing per year. As participation rates increase, the frequency of injuries related to softball is on the rise. Softball injuries can differ from baseball injuries, and only a small amount of current literature focuses exclusively on softball injuries. Orthopaedic surgeons need to be prepared to evaluate, diagnose, and treat common injuries sustained while playing softball. The purpose of this study is to investigate the mechanisms of injury that are commonly encountered by female athletes in competitive fast-pitch softball and review current safety initiatives that have been implemented to aide in injury prevention.

Sports-Related Injuries in Adolescent Athletes: A Systematic Review

Sports participation among adolescents is increasing, offering numerous health benefits and exposing them to the risk of sports-related injuries. This paper aims to understand that the prevalence and risk factors associated with these injuries are crucial for effective injury prevention and the overall well-being of adolescent athletes. This systematic review synthesizes the existing literature on sports-related injuries in adolescent athletes. A comprehensive search was conducted, yielding 11 relevant studies. The studies were analyzed to determine the prevalence of injuries and identify associated risk factors. A qualitative synthesis of the findings was performed. The included studies collectively highlight the significant burden of sports-related injuries among adolescent athletes, with prevalence rates ranging from 34.1% to 65%. Specific risk factors associated with these injuries include body mass index (BMI), physical activity patterns, age, gender, sport type, previous injuries, and training practices. Obese adolescents, those engaged in excessive weekly practice hours, younger athletes, and females were found to be at higher risk. Certain sports, such as soccer and football, exhibited higher injury rates. Sports-related injuries in adolescent athletes are a multifaceted issue influenced by various factors. Tailored injury prevention strategies are essential, considering the specific needs of adolescent athletes in different sports and age groups. Interventions should encompass physical and educational components, emphasizing proper warm-ups, protective equipment use, and injury prevention education. Longitudinal studies and standardized injury reporting systems are needed to monitor injury trends and evaluate prevention strategies effectively. This systematic review contributes to our understanding of sports-related injuries in adolescent athletes and underscores the importance of evidence-based injury prevention efforts.

Female Collegiate Athletes' Concussion Characteristics and Recovery Patterns: A Report from the NCAA-DoD CARE Consortium

Concussion has been described in the United States (US) collegiate student-athlete population, but female-specific findings are often underrepresented and underreported. Our study aimed to describe female collegiate student-athletes' initial injury characteristics and return to activity outcomes following concussion. Female collegiate student-athletes (n = 1393) from 30-US institutions experienced a concussion and completed standardized, multimodal concussion assessments from pre-injury through unrestricted return to play (uRTP) in this prospective, longitudinal cohort study. Initial injury presentation characteristics, assessment, and return to activity outcomes [<48-h (acute), return to learn, initiate return to play (iRTP), uRTP] were collected. We used descriptive statistics to report injury characteristics, return to activity outcomes, and post-injury assessment performance change categorization (worsened, unchanged, improved) based on change score confidence rank criteria across sport contact classifications [contact (n = 661), limited (n = 446), non-contact (n = 286)]. The median (25th to 75th percentile) days to return to learn was 6.0 (3.0-10.0), iRTP was 8.1 (4.8-13.8), and uRTP was 14.8 (9.9-24.0), but varied by contact classification. Across contact levels, the majority experienced worse SCAT total symptom severity (72.8-82.6%), ImPACT reaction time (91.2-92.6%), and BSI-18 total score (45.2-51.8%) acutely relative to baseline, but unchanged BESS total errors (58.0-60.9%), SAC total score (71.5-76.1%), and remaining ImPACT domains (50.6-66.5%). Our findings provide robust estimates of the typical female collegiate student-athlete presentation and recovery trajectory following concussion, with overall similar findings to the limited female collegiate student-athlete literature. Overall varying confidence rank classification was observed acutely. Our findings provide clinically-relevant insights for athletes, clinicians, researchers, and policymakers to inform efforts specific to females experiencing concussion.

Initial Mild Traumatic Brain Injury Characteristics and Recovery Patterns Among Females Across the United States Military Service Academies: A Report from the NCAA-DoD CARE Consortium

Mild traumatic brain injury (mTBI) has been described in the United States (US) military service academy cadet population, but female-specific characteristics and recovery outcomes are poorly characterized despite sex being a confounder. Our objective was to describe female cadets' initial characteristics, assessment performance, and return-to-activity outcomes post-mTBI. Female cadets (n = 472) from the four US military service academies who experienced a mTBI completed standardized mTBI assessments from pre-injury to acute initial injury and unrestricted return-to-duty (uRTD). Initial injury presentation characteristics (e.g., delayed symptoms, retrograde amnesia) and return-to-activity outcomes [i.e., return-to-learn, initiate return-to-duty protocol (iRTD), uRTD] were documented. Descriptive statistics summarized female cadets' injury characteristics, return-to-activity outcomes, and post-mTBI assessment performance change categorization (worsened, unchanged, improved) relative to pre-injury baseline using established change score confidence rank criteria for each assessment score. The median (interquartile range) days to return-to-learn (n = 157) was 7.0 (3.0-14.0), to iRTD (n = 412) was 14.7 (8.6-25.8), and to uRTD (n = 431) was 26.0 (17.7-41.8). The majority experienced worse SCAT total symptom severity (77.8%) and ImPACT reaction time (97.0%) acutely < 24-h versus baseline, but unchanged BESS total errors (75.2%), SAC total score (72%), BSI-18 total score (69.6%), and ImPACT verbal memory (62.3%), visual memory (58.4%), and visual motor speed (52.5%). We observed similar return-to-activity times in the present female cadet cohort relative to the existing female-specific literature. Confidence ranks categorizing post-mTBI performance were heterogenous and indicate multimodal assessments are necessary. Our findings provide clinically relevant insights to female cadets experiencing mTBI across the US service academies for stakeholders providing healthcare.

Sport level and sex differences in sport-related concussion among Japanese collegiate athletes: Epidemiology, knowledge, reporting behaviors, and reported symptoms

This study investigated the incidence of sport-related concussion (SRC) in sports, effect of athlete knowledge on reporting behavior differences between collegiate and non-collegiate athletes, and differences in SRC symptoms between sexes and level of participation. In this cross-sectional survey, 1 344 Japanese collegiate and non-collegiate athletes from a single institute were analyzed. Using a web-based survey, demographics, general SRC, knowledge of SRC, the most recent SRC reporting behaviors, and symptom presentation were examined. The prevalence of SRC during the academic year 2016-2017 was 2.68 (95% confidence interval [CI]: 1.88-3.69) across all sports. The prevalence of SRC was 33.3 (95% CI: 17.96-51.83) in rugby union and 8.33 (95% CI: 1.03-27.00) in women's soccer. The prevalence of SRC in males (3.47 [95% CI: 2.38-4.86] was 3.65 times higher than that in females (0.95 [95% CI: 0.26-2.41]). In total, the mean total score of knowledge was 5.30 (4.2) across 25 questions; dizziness was the most well-known symptom (867/1 344, 64.5%), followed by headache (59.3%). Being more emotional (44/1 345, 3.3%) was the least frequently known symptom. Level of participation did not affect scores (5.16 [3.96] vs. 5.52 [4.54]; p ​= ​0.131). All 87 disclosing participants experienced drowsiness and irritability and felt more emotional. In terms of sex and participant level, no significant differences were found in any symptoms. This study found very low rates of concussion education in Japan. Dissemination of concussion education is essential in the future to recognize concussion earlier and prevent severe concussive injury.

Reliability and Minimal Detectable Change of the Standardized Assessment of Reaction Time

CONTEXT

Postconcussion reaction time deficits are common, but existing assessments lack sport-related applicability. We developed the Standardized Assessment of Reaction Time (StART) tool to emulate the simultaneous cognitive and motor function demands in sport, but its reliability is unestablished.

OBJECTIVES

To determine the intrarater, interrater, and test-retest reliability of StART and to examine the dual-task effect, time effect, and relationships between StART and computerized and laboratory-based functional reaction time assessments.

DESIGN

Prospective cohort study.

SETTING

Clinical laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty healthy, physically active individuals (age = 20.3 ± 1.8 years, females = 12, no concussion history = 75%).

MAIN OUTCOME MEASURE(S)

Participants completed the StART, computerized reaction time (Stroop task via CNS Vital Signs), and laboratory-based jump landing and cutting reaction time under single-task and dual-task (subtracting by 6s or 7s) cognitive conditions at 2 testing sessions a median of 7 days apart. We used intraclass correlation coefficients (ICCs), repeated-measure analysis of variance, and Pearson r correlations to address our aims.

RESULTS

Overall, good to strong interrater (ICC [2,k] range = 0.83-0.97), intrarater (ICC [3,k] range = 0.91-0.98), and test-retest (ICC [3,k] range = 0.69-0.89) reliability were observed. A significant reaction time assessment-by-cognitive condition interaction was present (P = .018, ηp2 = 0.14), with StART having the largest dual-task effect. Main time effects for dual-task conditions were seen across all reaction time assessments (mean difference = -25 milliseconds, P = .026, ηp2 = 0.08) with improved performance at the second testing session. No StART outcomes correlated with computerized reaction time (P > .05), although some correlated with single-task (r range = 0.42-0.65) and dual-task (r range = 0.19-0.50) laboratory cutting reaction time.

CONCLUSIONS

The StART demonstrated overall reliable performance relative to other reaction time measures. Reliability coupled with a strong dual-task effect indicates that StART is a valid measure for examining functional reaction time and may have future utility for sport-related concussion return-to-play decision-making.

Head Impact Exposure in Female Collegiate Soccer by Activity Type

Soccer, one of the most popular sports in the world, has one of the highest rates of sports-related concussions. Additionally, soccer players are frequently exposed to nonconcussive impacts from intentionally heading the ball, a fundamental component of the sport. There have been many studies on head impact exposure in soccer, but few focus on soccer practices or practice activities. This study aimed to characterize the frequency and magnitude of head impacts in National Collegiate Athletic Association Division I female soccer practice activities using a custom-fit instrumented mouthpiece. Sixteen players were instrumented over the course of 54 practice sessions. Video analysis was performed to verify all mouthpiece-recorded events and classify practice activities. Category groupings of practice activities include technical training, team interaction, set pieces, position-specific, and other. Differences in head impact rates and peak resultant kinematics were observed across activity types and category groupings. Technical training had the highest impact rate compared to other category groupings. Impacts occurring during set piece activities had the highest mean kinematic values. Understanding drill exposure can help inform coaches on training plans aimed to reduce head impact exposure for their athletes.

Lacrosse-related injuries in boys and girls treated in U.S. emergency departments, 2000-2016

BACKGROUND

Lacrosse is one of the fastest-growing sports in the United States. Its rules regarding permitted contact differ by sex and age. There are no known studies using a nationally representative data set to analyze lacrosse injury patterns over several years by sex and age in the youth population.

METHODS

A retrospective analysis was performed using data from the National Electronic Injury Surveillance System for youth aged 11-18 years who were treated for lacrosse-related injuries in U.S. emergency departments from 2000 to 2016. Based on our review of the case narratives, we created and coded a new injury-mechanism variable. We generated national estimates from 6406 cases.

RESULTS

An estimated 206,274 lacrosse-related injuries to youths aged 11-18 years were treated in U.S. emergency departments from 2000 to 2016. The rate of injuries per 10,000 significantly increased from 1.9 in 2000 to a peak of 5.3 in 2012 (p < 0.0001), followed by a significant decrease to 3.4 in 2016 (p = 0.020). Injury mechanism, body part injured, and diagnosis differed by sex. Boys were 1.62 times (95% confidence interval (95%CI): 1.25-2.09) more likely than girls to be injured by player-to-player contact. Girls were 2.21 times (95%CI: 1.96-2.49) more likely than boys to have non-contact injuries. Overall, as age increased, the percentage of injuries from lacrosse sticks decreased and player-to-player contact increased.

CONCLUSION

Despite additional protective regulations in the sport, lacrosse is an important source of injury where we continue to see differences by sex and age. This study supports the continuation, modification, and addition of rules aimed at reducing lacrosse injury risk.

Investigating the association between subjective and objective performance-based cognitive function among former collegiate football players

OBJECTIVE

Studies have observed variable associations of prior contact sport participation with subjective and objective measures of cognitive function. This study directly investigated the association between subjective self-report and objective performance-based cognition among former collegiate football players, as well as its relationship to self-reported concussion history.

METHODS

Former collegiate football players (N = 57; mean age = 37.9 years [SD = 1.49]) retired from sport 15-years prior were enrolled. Linear regression models examined associations between subjective cognition (Quality of Life in Neurological Disorders Cognitive Functioning-Short Form), and performance on a neuropsychological battery. Domain specific (executive function) metrics of subjective (Behavior Rating Inventory of Executive Function-Adult) and objective cognition were also exclusively examined. Associations between self-reported concussion history with subjective and objective measures were tested. Potential influential factors (sleep quality and distress) were included as covariates.

RESULTS

Subjective cognition was not significantly associated with any objective measures of cognitive functioning (p's > .05). Greater self-reported concussion history was inversely associated with subjective cognition (B = -2.49, p = .004), but not objective performance-based cognition (p's > .05). Distress was significantly related to all metrics of subjective cognition (p's < .001) as well as performance on delayed recall and verbal fluency (p's < .05). Sleep quality was only significantly related to timed visuospatial sequencing (p = .033).

CONCLUSIONS

Reliance on self-reported measures of cognitive functioning alone is insufficient when assessing cognition in former contact sport athletes. Assessment of other factors known to influence subjective cognitive complaints should also be examined in determining the presence of cognitive deficits.

Sport-related concussion disclosure in women's rugby-A social identity approach

Introduction

Sport-related concussion (SRC) is a risk of collision sports such as women's rugby. To support appropriate SRC diagnosis and management, an understanding of the factors that encourage SRC disclosure is necessary. To date, research has focused on ascertaining individual player knowledge and attitudes towards SRC disclosure.

Methods

We chose to investigate the potential influence of group identification effects by examining the role of social identity on SRC disclosure in elite women's rugby. Seventeen elite players from the United Kingdom and Ireland were interviewed and their transcripts thematically analysed.

Results

The data highlighted that the players shared a very strong social identity as women in rugby and were acutely aware that their experiences were different to their male counterparts. The shared social identity had both positive and negative implications for SRC disclosure. The players interviewed did not feel comfortable disclosing their symptoms to their coach and often felt that medical staff either did not listen to them or were unavailable to them. Mediators such as communication, trust in medical teams, perceived pressure, positive injury management experience, and player role models were identified.

Discussion

This research could be utilised to inform sport psychology interventions to enhance SRC disclosure in elite women's rugby.

Mild traumatic brain injury and sports-related concussion

Mild traumatic brain injury (mTBI) and concussion are equivalent terms for the sequela of injury to the head that disrupts brain functioning. Various forces may be causative from seemingly innocuous bumps to the head resulting from sports-related injuries to more severe blows to the head. However, the postconcussive motor, cognitive, emotional, and psychosocial sequelae can be just as devastating and long lasting, leading to loss of independent function and safe performance of activities. Taken together, they pose a significant challenge to recovery, requiring a multifaceted dynamic rehabilitative strategy. The current systems of health care pose challenges to suboptimal management of sports-related concussion (SRC) that goes beyond the acute injury, and into the school setting, failing to be identified by school staff, and inconsistencies in communicating medical information regarding school modifications, follow-up health services, or concussion-related educational services. Children who sustain SRC at different ages face different challenges. Young children face increased vulnerability due to SRC that coincides with periods of brain motor maturation and development.

Risk factors for shoulder injuries in handball: systematic review

BACKGROUND

Handball is a sport with a high number of severe injuries. The shoulder is one of the most commonly injured joints, with an average prevalence of 17-41%.

OBJECTIVE

The primary aim is to identify the most significant risk factors related to shoulder injuries in handball. The secondary aim is to propose recommendations based on the available evidence concerning potential injury prevention strategies.

METHODS

Systematic searches of PubMed, MEDLINE, CINAHL, Proquest, SPORTDiscus, Web of Science, EMBASE, and Scopus were undertaken for peer reviewed articles published between 15 July 1995 and 15 July 2019. The same search strategy was repeated on 24 April 2022. Prospective cohort studies, written in English and published in a journal with a peer-review process aiming to investigate at least one modifiable or/and a non-modifiable potential risk factor for shoulder injuries, specifically in handball players, were included. Only papers published after 1995 were included. The methodological quality of the eligible studies was assessed using the modified version of the Downs and Black Checklist. The Best Evidence Synthesis (BES) approach was used for synthesizing and reporting the results.

RESULTS

1849 studies were identified, of which 8 were included. A total of 2536 (males = 1354, females = 1182) participants of which 2522 were handball athletes, were included. Four of the eight studies were rated as high methodological quality studies (> 85%) while the rest were rated as medium (50-85%). The risk factors for shoulder injuries in handball identified in the studies were strength imbalances (n = 6), glenohumeral range of motion (ROM) imbalances (n = 5), scapular dyskinesis (n = 5), incorrect dosage of training load (n = 2), previous injury (n = 1), sex (n = 2), player's position, school grade, playing level (n = 1), altered shoulder joint position sense (n = 1).

CONCLUSION

Overall, from all the risk factors evaluated, there was strong evidence that the weakness of the shoulder external rotator muscles and the female sex increase the probability of shoulder injury in handball athletes. Nevertheless, the evidence for the other risk factors was moderate due to the methodological quality and the limited number of studies.

PROTOCOL REGISTRATION

PROSPERO ID: CRD42020138233.

Sex comparisons in neuropsychological functioning and reported symptoms following a sports-related concussion among high school athletes

The aim of this study was to compare the neuropsychological functioning and symptoms of female and male high school athletes following a single concussion during the school year. The baseline test scores of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) of 309 concussed athletes (169 females, 221 males) in varied sports were obtained. After a sport-related concussion, the athletes were re-administered the ImPACT, on the average, 7.25 days after the injury. MANCOVA compared the ImPACT baseline scores, post-concussion scores, and baseline-to-post-concussion changes of the female and male athletes, with p set at 0.01. The only significant sex comparison found females performing better on baseline visual motor speed (p < 0.001). Otherwise, no sex differences were found in baseline test scores, post-concussion scores, and baseline-to-post-concussion changes. The findings tentatively suggest that there are insignificant sex differences in the consequences of sport-related concussion after a week post-injury. Future studies on sex comparisons after a concussion are needed focusing on the acute and sub-acute phases of the recovery period.

Sex-related differences in sternocleidomastoid muscle morphology in healthy young adults: A cross-sectional magnetic resonance imaging measurement study

BACKGROUND

Changes in sternocleidomastoid (SCM) muscle cross-sectional area (CSA) and volume may contribute to neck-related concussion symptoms and whiplash-associated disorders. Magnetic resonance imaging (MRI) data on healthy SCM morphology can provide information that may lead to targeted treatment protocols.

OBJECTIVES

To examine sex-related differences in MRI-based SCM CSA, SCM volume and neck area in healthy young adults, to analyze associations between measurements and participant variables and to assess inter-rater reliability for measurement quantification.

DESIGN

Cross-sectional study.

METHODS

13 males and 14 females underwent MRI scans. Slices obtained from C3-C7 were analyzed by three raters. SCM CSA at C4, total SCM volume from C3-C7 and neck area at C4 were quantified. Measurements were calculated as absolute and normalized values by body mass. Multivariable regression was used to analyze associations between normalized measurement values and participant variables. Inter-rater reliability was determined using intraclass correlation coefficients (ICC).

RESULTS

Females had significantly lower normalized overall average SCM CSA (mean difference 1.3 mm²/kg (95% CI 0.4-2.2, p = 0.006) and total SCM volume (mean difference 140.8 mm3/kg (95% CI 66.1-215.5, p < 0.001) than males. Regression models indicated female sex was associated with lower normalized overall average SCM CSA (p = 0.004) and total SCM volume (p < 0.001). Inter-rater reliability was excellent for SCM CSA (ICC_3,3 = 0.909), SCM volume (ICC_3,3 = 0.910) and neck area (ICC_3,3 = 0.995).

CONCLUSIONS

These results enhance our understanding of sex-related differences in SCM morphology and will inform future research and clinical practice related to cervical muscle injury.

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.

Mobile Subthreshold Exercise Program (MSTEP) for concussion: study protocol for a randomized controlled trial

BACKGROUND

Subthreshold exercise, defined as aerobic exercise below the level that causes symptoms, has been utilized as a treatment for youth with persistent postconcussive symptoms (PPCS), but there is currently little evidence to guide use. In addition, prior studies of exercise for PPCS have all required multiple in-person visits. We developed a virtual approach for delivering subthreshold exercise to youth with PPCS called the Mobile Subthreshold Exercise Program (MSTEP), and we have now been funded to conduct a large national randomized controlled trial (RCT) to test its efficacy for reducing concussive symptoms and improving health-related quality of life.

METHODS

This investigation is an RCT comparing MSTEP to an active control. We will recruit 200 adolescents 11-18 years old with postconcussive symptoms persisting for at least 1 week but less than 1 year. Youth will be randomized to receive either 6 weeks of subthreshold exercise (MSTEP) or a stretching condition (control). Youth and parents will complete surveys of concussive symptoms at baseline, weekly during the intervention, and at 3 and 6 months. The primary outcomes will be trajectory of concussive symptoms and health-related quality of life over the 6 months of the study. Secondary outcomes will include depression, anxiety, and sleep quality. We will also assess potential mediators of treatment effects including moderate-vigorous physical activity and fear avoidance of concussive symptoms.

DISCUSSION

This multisite RCT of MSTEP will provide vital information regarding the efficacy of a virtually delivered subthreshold exercise program for youth with PPCS, and insight regarding potential mediators of treatment effects, including objectively measured physical activity and fear avoidance of concussive symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04688255. Registered on December 29, 2020.

Tau pathology, metal dyshomeostasis and repetitive mild traumatic brain injury: an unexplored link paving the way for neurodegeneration

Repetitive mild traumatic brain injury (r-mTBI), commonly experienced by athletes and military personnel, causes changes in multiple intracellular pathways, one of which involves the tau protein. Tau phosphorylation plays a role in several neurodegenerative conditions including chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disorder linked to repeated head trauma. There is now mounting evidence suggesting that tau phosphorylation may be regulated by metal ions (such as iron, zinc and copper), which themselves are implicated in ageing and neurodegenerative disorders such as Alzheimer's disease (AD). Recent work has also shown that a single TBI can result in age-dependent and region-specific modulation of metal ions. As such, this review explores the link between TBI, CTE, ageing and neurodegeneration with a specific focus on the involvement of (and interaction between) tau pathology and metal dyshomeostasis. The authors highlight that metal dyshomeostasis has yet to be investigated in the context of repeat head trauma or CTE. Given the evidence that metal dyshomeostasis contributes to the onset and/or progression of neurodegeneration, and that CTE itself is a neurodegenerative condition, this brings to light an uncharted link that should be explored. The development of adequate models of r-mTBI and/or CTE will be crucial in deepening our understanding of the pathological mechanisms that drive the clinical manifestations in these conditions and also in the development of effective therapeutics targeted towards slowing progressive neurodegenerative disorders.

Sex and Gender Science: The World Writes on the Body

Sex and Gender Science seeks to better acknowledge that the body cannot be removed from the world it inhabits. We believe that to best answer any neuroscience question, the biological and the social need to be addressed through both objective means to learn, "how it is like" and subjective means to learn, "what it is like." We call bringing the biological and social together, "Situated Neuroscience" and the mixing of approaches to do so, Very Mixed Methods. Taken together, they constitute an approach to Sex and Gender Science. In this chapter, we describe neural phenomena for which considering sex and gender together produces a fuller knowledge base: sleep, pain, memory, and concussion. For these brain phenomena examples, studying only quantitative measures does not reveal the full impact of these lived experiences on the brain but studying only the qualitative would not reveal how the brain responds. We discuss how Sex and Gender Science allows us to begin to bring together biology and its social context and acknowledge where context can contribute to resolving ignorance to offer more expansive, complementary, and interrelating pictures of an intricate neuro-landscape.

Concussion Management Guidelines Neglect Auditory Symptoms

Tinnitus, noise sensitivity, and hearing difficulties are commonly reported secondary to head injury. These auditory deficits have been shown to negatively impact daily functioning, and yet, often go unnoticed by health care professionals. The purpose of this editorial is to explain why it is essential for clinical practice guidelines that address the management of patients who have experienced a head injury to incorporate assessment and rehabilitation of auditory symptoms.

Non-Time-Loss and Time-Loss Injuries in Secondary School Girls' Volleyball Athletes: A Report From the National Athletic Treatment, Injury, and Outcomes Network Surveillance Program

CONTEXT

Volleyball is a popular sport with a risk of injury to the entire body. Insight into non-time-loss (NTL) and time-loss (TL) injuries is needed to inform seasonal injury trends that may lead to appropriate prevention and management strategies. This study provides a descriptive analysis of volleyball injuries among secondary school athletes.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Data were collected from 72 secondary schools, representing 135 team seasons of data from the National Athletic Treatment, Injury, and Outcomes Network Surveillance Program (2014-2015 to 2018-2019 academic years). Injury counts, injury rates (IR) per 1000 athlete exposures (AEs), and incidence rate ratios (IRR) were reported with 95% confidence intervals (CIs).

RESULTS

In total, 529 injuries over 193,858 AEs for girls' volleyball were captured, producing an IR of 2.73/1000AEs (95% CI = 2.50-2.96). The overall IR was highest during the preseason compared with regular season (IRR = 1.31, 95% CI = 1.09-1.59). Overall IRs were higher in competition (IR: 3.56, 95% CI = 3.07-4.05) compared with practice (IR: 2.38, 95% CI = 2.12-2.64; IRR = 1.49, 95% CI = 1.25-1.79). Common body locations injured were ankle (n = 141, 26.7%; NTL: n = 56, 21.7%; TL: n = 85, 31.7%), knee (n = 61, 11.5%; NTL: n = 33, 12.8%, TL: n = 28, 10.5%), hand/wrist (n = 59, 11.2%; NTL: n = 32, 12.4%, TL: n = 27, 10.1%), and head/face (n = 62, 11.7%; NTL: n = 14, 5.4%; TL: n = 47, 17.5%).

CONCLUSIONS

Volleyball IRs were highest in preseason and during competition. Most injuries affected the lower-extremity which is notable considering the high upper-extremity load in volleyball. Consideration of strategies to reduce injuries prior to the start of the formal sports season may be needed to help reduce the incidence of preseason injuries.

National Athletic Trainers' Association Position Statement: Reducing Intentional Head-First Contact Behavior in American Football Players

OBJECTIVE

To provide evidence-based recommendations for reducing the prevalence of head-first contact behavior in American football players with the aim of reducing the risk of head and neck injuries.

BACKGROUND

In American football, using the head as the point of contact is a persistent, well-documented, and direct cause of catastrophic head and cervical spine injury. Equally concerning is that repeated head-impact exposures are likely to result from head-first contact behavior and may be associated with long-term neurocognitive conditions such as dementia, depression, and chronic traumatic encephalopathy.

CONCLUSIONS

The National Athletic Trainers' Association proposes 14 recommendations to help the certified athletic trainer, allied health care provider, coach, player, parent, and broader community implement strategies for reducing the prevalence of head-first contact in American football.

Evaluating Adult Decision-Making Modifiers in Support of Youth Contact-Sport Participation

CONTEXT

Nearly 44 million youth participate in organized youth sports programs in the United States each year. However, approximately 25% of parents have considered removing their children from sports due to the fear of concussion.

OBJECTIVE

To determine which adult decision-making modifiers (eg, gender, educational attainment, career type) influenced support for youth contact-sports participation.

DESIGN

Cross-sectional study.

SETTING

Midwestern university and medical center.

PATIENTS OR OTHER PARTICIPANTS

Convenience sample of staff and faculty (N = 5761; 73.9% female) from 2017 to 2018.

MAIN OUTCOME MEASURE(S)

Support for youth contact-sports participation using multivariate binary logistic regression to calculate odds ratios and 95% CIs.

RESULTS

The sample was split between adults with children (AWCs; n = 3465, age = 45.39 ± 13.27 years, 76.72% female) and adults without children (AWOCs; n = 2296, age = 30.84 ± 9.01 years, 70.26% female). Among AWCs, those who obtained a bachelor's degree or higher were more likely to support contact-sports participation. Females were more inclined to allow all contact sports, specifically football (odds ratio [OR] = 2.22; 95% CI = 1.64, 3.01) and ice hockey (OR = 1.98; 95% CI = 1.42, 2.78). Overall, previous adult sport participation, increasing number of children, and child gender were significant modifying variables in greater support of youth contact-sports participation among AWCs (P < .001). Among AWOCs, previous sport participation in football (OR = 3.27; 95% CI = 2.14, 4.87), ice hockey (OR = 4.26; 95% CI = 2.23, 8.17), or soccer (OR = 2.29; 95% CI = 1.48, 3.54) increased the likelihood of an adult supporting contact-sports participation. Lastly, all adults were less inclined to support a daughter participating in any contact sport than a son.

CONCLUSIONS

These results reveal adult- and child-specific variables that may influence youth contact-sports participation. These decisions may be developed through the lens of certain gender role beliefs and may lead adults to perceive certain sports as more appropriate for sons than daughters.

United States Air Force Academy Cadets' Unprompted Knowledge of Concussions and "Bell Ringers" or "Dings": Perceived Differences and Similarities

CONTEXT

After a possible concussion mechanism, cadets are unlikely to have a list of concussion signs and symptoms at their disposal. As such, unprompted concussion knowledge may be an essential factor in personal recognition of injury.

OBJECTIVE

To explore determinants that contributed to United States Air Force Academy (USAFA) cadets' disclosure of a concussion. This research focused on 1 of 8 overall discovered themes of unprompted concussion knowledge.

DESIGN

Qualitative study.

SETTING

Military academy.

PATIENTS OR OTHER PARTICIPANTS

Cadets at the USAFA (males = 23, females = 11, age = 19.91 ± 1.14 years).

MAIN OUTCOME MEASURE(S)

We conducted 34 semistructured interviews. The transcribed text was analyzed in a 5-cycle process. From this process, 8 overall themes emerged, including unprompted concussion knowledge. Subthemes were concussion definition, concussion symptoms, "bell-ringer" or "ding" definition, "bell-ringer" or "ding" symptoms, and concussion versus "bell ringer" or "ding."

RESULTS

Many participants were able to describe a concussion fairly accurately. The most commonly listed concussion signs and symptoms were dizziness (n = 22/34, 64.7%); "can't remember"/"memory loss"/"forgetful" (n = 19/34, 55.9%); and headache (n = 16/34, 47.1%). The cadet participants characterized the most common bell-ringer or ding signs and symptoms as dizziness (n = 2/34, 5.9%) and headache (n = 2/34, 5.9%). Cadets also described how a bell ringer or ding differs from a concussion, often commenting that concussions were more severe than bell ringers or dings.

CONCLUSIONS

Overall, USAFA cadet participants listed common concussion signs and symptoms. However, they perceived differences between a concussion and a bell ringer or ding. Although decreasing the use of colloquial terms for concussion is recommended, use of these terms when examining a concussion history may be helpful. Concussion-education interventions should continue to focus on describing concussion signs and symptoms using cadets' own words to describe the injury (eg, "forgetful") but differentiating between what may and may not be a concussion and encouraging individuals to consult health care providers regarding possible concussion symptoms.

Head Games: A Systematic Review and Meta-analysis Examining Concussion and Head Impact Incidence Rates, Modifiable Risk Factors, and Prevention Strategies in Youth Tackle Football

OBJECTIVES

The aims were to (1) examine the rates and mechanisms of concussion and head impact in youth football (high school level or younger); (2) identify modifiable risk factors for concussion and head impact; and (3) evaluate the effectiveness of prevention strategies in tackle football at any level.

METHODS

Nine databases (CINAHL Plus with Full Text; Cochrane Central Register of Controlled Trials; EMBASE; ERIC; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily; ProQuest Dissertations & Theses Global Database; PsycINFO; Scopus; and SPORTDiscus with Full Text) were searched using the search strategy focusing on four main concepts: concussion/head impact, tackle football, modifiable risk factors, and primary prevention. Two reviewers completed title, abstract, and full-text screening as well as risk of bias assessment (using the Downs and Black checklist), with a third author available to resolve any disagreements.

MAIN RESULTS

After removing duplicates, 1911 articles were returned. Fifty-eight articles were included in the review and 20 in the meta-analysis. The overall combined rates of concussion (including game and practice-related concussion) based on the meta-analysis were 0.78 concussions/1000 athlete exposures [95% confidence interval (CI) 0.67-0.89] for high school football (ages 13-19) and 1.15 concussions/1000 athlete exposures (95% CI 0.89-1.41) for minor football players (ages 5-15). There is evidence that contact training and practice contact restrictions have reduced the rate of head impacts and concussion. Heads Up Football (an intervention focused on coach education and contact training) has been shown to reduce the rate of concussion by 32% and head impacts by 38% amongst high school football players. Limiting contact practices in high schools to 2 days per week reduced practice head impacts per player-season by 42%, and limiting full contact in practice to 75 min per week in the second week of the season and 60 min in week 3 and beyond resulted in a 54% decrease in the practice-related concussion rate (p = 0.003).

CONCLUSIONS

This review identified a critical need for interventions to address the high rates of concussion and head impact in youth football. To date, contact training and contact restrictions have the strongest evidence supporting their effectiveness at reducing these rates. Future research should use consistent concussion definitions and validated injury surveillance systems, and ensure complete reporting of participant characteristics and sampling details. Prospero ID CRD42020193775.

Overview of Sport-Specific Injuries

Athletes are at risk for a variety of injuries not typically sustained in everyday life. The team physician must be capable of not only identifying and treating injuries as they occur, but he or she must be armed with the knowledge to minimize the risk of injuries before they occur. This review serves to provide an overview of the various sport-specific injuries typically encountered by team physicians. Injuries are grouped by body part and/or organ system, when possible. We do not aim to cover in detail the various treatments for these injuries; rather, we hope that this article provides a comprehensive overview of sport-specific injury, and demonstrate the well-roundedness in skills that must be possessed by team physicians.

High Injury and Concussion Rates in Female Youth Team Sport: An Opportunity for Prevention

The aim of this study was to investigate sport-related injury rates, types, locations, and mechanisms in female youth team sports.This was a secondary analysis of a cross-sectional study. An anonymous online survey was administered to high school students (ages 14-19) in Canada. The survey included questions regarding demographic information, sport participation and self-reported injuries sustained in the past year. Results were analyzed for girls who reported playing a top ten team sports for female participation. For girls participating in team sports, the overall injury rate was 55.5 injuries/100 participants/year. The rate of at least one concussion was 9.4 concussions/100 participants/year. Injury and concussion rates were highest in ringette (Injury rate=42.9 injuries/100 participants/year, Concussion rate=19.0 concussions/100 participants/year) and rugby (Injury rate=40.0, Concussion rate=15.3). The top three most serious injury locations were the knee (24.7%), ankle (21.6%) and head (16.1%). The most common injury types were joint/ligament sprain (26.71%), fracture (13.0%) and concussion (11.8%). Contact mechanisms accounted for 73.4% of all serious injuries reported in girls team sports.Team sport injury rates are high in female youth team sports. Specific consideration of sport-specific injury rates, types and mechanisms in girls' team sports will inform development and evaluation of targeted sport-specific prevention strategies.

Concussion symptoms and temporary accommodations using a student-centered return to learn care plan

BACKGROUND

Many students return to school after concussion with symptoms but without formal support.

OBJECTIVE

To examine concussion symptoms and temporary academic accommodations during school use of a four-week student-centered return to learn (RTL) care plan.

METHODS

Five public high schools used the RTL care plan and contributed student-level data after student report of concussion. Data on concussion symptoms, temporary academic accommodations corresponding to reported symptoms, and accommodations provided during RTL care plan use were examined.

RESULTS

Of 115 students, 55%used the RTL care plan for three (34%) or four (21%) weeks. Compared to students whose symptoms resolve within the first two weeks, students who used the RTL care plan for three or four weeks reported more unique symptoms (P = 0.038), higher total severity score (P = 0.005), and higher average severity per symptom (P = 0.007) at week one. Overall, 1,127 weekly accommodations were provided. While least reported, emotional symptoms received corresponding accommodations most often (127/155 reports: 82%of occurrences).

CONCLUSIONS

Use of an RTL care plan can facilitate the RTL of students with a concussion and may aid in the identification of students who are in need of longer-term support.

Retrospective survey of youth sports participation: Development and assessment of reliability using school records

Many youths participate in sports, and it is of interest to understand the impact of youth sports participation on later-life outcomes. However, prospective studies take a long time to complete and retrospective studies may be more practical and time-efficient to address some questions. We pilot a retrospective survey of youth sports participation and examine agreement between respondent’s self-reported participation with high school records in a sample of 84 adults who graduated from high school between 1948 and 2018. The percent agreement between our survey and the school resources for individual sports ranged between 91.5% and 100%. These findings provide preliminary evidence for the reliability of retrospective self-report of youth sports participation. This survey may serve as an efficient approach for evaluating relationships between involvement in youth sports and health outcomes later in adulthood.

Diversifying sport-related concussion measures with baseline balance and ocular-motor scores in professional Zambian football athletes

PURPOSE

Normative values of common sport-related concussion assessment tools may assist clinical diagnosis and management. However, current baseline normative values are not representative of athletic participants across international domains. This study develops healthy baseline norms on the Balance Error Scoring System (BESS), and King-Devick (K-D), providing baseline reference values for professional Zambian football athletes.

METHODS

Of the 125 male participants (aged 24.48 ± 5.41 years) screened for this study, 9 (7.2%) reported a previous history of concussion, 98 (78.4%) completed the Balance Error Scoring System and 88 (70.4%) completed the King-Devick. Descriptive statistics calculated for the BESS and the K-D test included mean, standard deviation, median, interquartile range (IQR), and percentiles ranks.

MAIN FINDINGS

Participants scored a mean ± standard deviation of 10.15 ± 5.6 and a median [IQR] of 9 [6-12.25] errors on the total BESS and completed the K-D test in a mean ± standard deviation 56.85 ± 10.55 seconds and a median [IQR] 55.28 [48.7-64.8] seconds.

CONCLUSIONS

Cross-cultural awareness and management of sport-related concussion are continuously improving the safety and well-being of athletic participants around the world. The diverse representation in these data may aid in interpretation of post-injury performance during sport-related concussion management in Zambia. This study develops baseline reference values currently lacking within African cultures and demonstrates the feasibility and global clinical utility of two sport-related concussion assessment resources.

Sex Differences and Reporting of SCAT-5 Concussion Symptoms in Adolescent Athletes

OBJECTIVE

To elucidate specific symptoms that may differ between adolescent female and male athletes after a sports-related concussion (SRC) and identify symptoms that may require greater clinical attention by medical and athletic staff.

DESIGN

Prospective.

SETTING

This study is part of a larger research project conducted at clinics in the North Texas Concussion Network (ConTex) Registry.

PARTICIPANTS

Subjects (N = 491) aged 12 to 18 years who sustained a diagnosed SRC within 30 days of clinic visit.

INDEPENDENT VARIABLES

Sex (female vs male). Covariates included age, race, current mood (anxiety and depression), learning disability/ADHD, and time to clinic.

MAIN OUTCOME MEASURES

Twenty-two individual postconcussion symptoms as measured by the Post-Concussion Symptom Scale from the Sport Concussion Assessment Tool-5 (SCAT-5).

RESULTS

Girls endorsed higher levels of anxiety and depression symptoms at initial clinic visit. analysis of covariance results revealed that girls had significantly greater symptom severity of headache, dizziness, sensitivity to light, sensitivity to noise, pressure in the head, feeling slowed down, fatigue, and drowsiness than boys. Ordinal logistic regression results also revealed that girls had significantly greater predicted odds of higher symptom severity on these 8 symptoms and in trouble concentrating than boys.

CONCLUSIONS

Closer examination of specific symptoms with attention to patients' current levels of anxiety and depression symptoms may better inform medical and athletic staff to anticipate and address symptoms that may present greater challenges for adolescent girls than boys.

Removal From Activity After Sports- Related Concussion in Sex-Comparable Sports From the Michigan High School Athletic Association

BACKGROUND

Research has demonstrated that female athletes are more likely to report their sports-related concussion (SRC) symptoms compared with male athletes; however, it is unknown if these reporting behaviors correspond to immediate removal from activity in sex-comparable sports.

PURPOSE

To compare the incidence of high school student-athletes removed and not removed from activity after SRC in sex-comparable sports in Michigan.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Participants included student-athletes diagnosed with SRC participating in Michigan High School Athletic Association-sponsored athletic activities (22 sex-comparable sports) between 2016 and 2019. All SRCs were recorded in the association's Head Injury Reporting System (HIRS) by certified athletic trainers, administrators, or coaches. Removal from activity indicated that the student-athlete was removed from play at the time of an injury event. If the student-athlete reported that his or her suspected injury event occurred earlier during activity or if symptom onset was delayed, "not removed from activity" was entered into the HIRS. Incidence proportions were calculated by dividing SRCs not removed by total SRCs in each sport. Risk ratios were calculated by dividing the incidence proportions of girls not removed by boys not removed in each sport.

RESULTS

A total of 4418 (2773 female, 1645 male) SRCs were reported, with the most occurring in female soccer players (n = 1023). Overall, 515 girls and 243 boys were not removed from activity, resulting in incidences of 0.19 (95% CI, 0.17-0.20) and 0.15 (95% CI, 0.13-0.17), respectively. Across all sports, girls were 1.26 (95% CI, 1.09-1.45) times as likely to not be removed from activity compared with boys. Of the sports with the most SRCs-soccer, basketball, baseball/softball, and lacrosse-girls had 1.37 (95% CI, 1.09-1.72), 1.15 (95% CI, 0.89-1.47), 1.19 (95% CI, 0.77-1.84), and 1.35 (95% CI, 0.94-1.95) times the risk of not being removed, respectively.

CONCLUSION

Girls were at greater risk of not being removed from activity compared with boys in sex-comparable sports. Results from this study should be incorporated into SRC education in Michigan and potentially elsewhere to inform affiliated personnel of potential sex differences and protect female student-athletes from further harm.

Post-traumatic headache attributed to traumatic brain injury: classification, clinical characteristics, and treatment

Post-traumatic headache is a common sequela of traumatic brain injury and is classified as a secondary headache disorder. In the past 10 years, considerable progress has been made to better understand the clinical features of this disorder, generating momentum to identify effective therapies. Post-traumatic headache is increasingly being recognised as a heterogeneous headache disorder, with patients often classified into subphenotypes that might be more responsive to specific therapies. Such considerations are not accounted for in three iterations of diagnostic criteria published by the International Headache Society. The scarcity of evidence-based approaches has left clinicians to choose therapies on the basis of the primary headache phenotype (eg, migraine and tension-type headache) and that are most compatible with the clinical picture. A concerted effort is needed to address these shortcomings and should include large prospective cohort studies as well as randomised controlled trials. This approach, in turn, will result in better disease characterisation and availability of evidence-based treatment options.

Reference Values for the Headache Impact Test-6 Questionnaire

OBJECTIVE

To determine reference values for the Headache Impact Test-6 (HIT-6) in a young, physically active cohort and to examine the influence of sex, concussion history, headache history, and competitive sport level on HIT-6 scores.

DESIGN

Cross-sectional.

SETTING

United States Service Academy.

PARTICIPANTS

United States Service Academy cadets (N=2678) completed an HIT-6 questionnaire as part of their annual concussion baseline assessment. Cadets with a recent concussion were excluded from baseline testing.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Reference values were calculated and stratified by sex, concussion history, headache history, and competitive sport level. Mann-Whitney U and Kruskal-Wallis tests were used to examine the effect of sex, concussion history, headache history, and competitive sport level on HIT-6 scores (P<.05).

RESULTS

Of the 3599 cadets baselined, 2687 cadets (23% female) agreed to participate in the study and completed the HIT-6. Female participants reported significantly worse HIT-6 scores compared with male participants both with (P<.001) and without (P<.001) a concussion history. In both sexes, participants with a headache history reported worse scores than those with no headache/concussion history and a concussion history (all P<.005). Female cadets who participated in intramural athletics reported worse HIT-6 scores at baseline than female intercollegiate athletes (P=.003).

CONCLUSIONS

This is the first study to stratify HIT-6 data by sex, concussion history, headache history, and sport level in a collegiate population at risk for concussions. Sex and headache history appear to influence HIT-6 scores and should be given special consideration when interpreting health-related quality of life deficits due to headache.

Prevalence of Dentofacial Injuries and Concussions Among College Athletes and Their Perceptions of Mouthguards

PURPOSE

The purpose of this study was to determine the rates of dento-facial injuries and concussions among National Collegiate Athletic Association (NCAA) division 1 college athletes and their perceptions of mouth-guards and their protection role in injury prevention.

MATERIALS AND METHODS

A specific survey regarding the experiences of dento-facial injuries and concussions, attitudes towards the mouthguards, and knowledge of dental first aid was distributed to 682 NCAA division I college athletes registered at Columbia University. The independent predictor variable was sport type (contact versus noncontact). The dependent outcome variables were dental injury rate, facial injury rate, concussion rate, mouthguard use, knowledge of dental first aid. Chi-squared and independent sample tests were used for statistical analysis.

RESULTS

The mean age of the athletes was 19.4 years (range: 17 to 22). 107 (47.6%) athletes were male. Only 62 (27.6%) athletes reported mouthguard use during gameplay. The most popular choice of mouthguard was the mouth-molded type (56.7%). Mouthguard use was significantly more prevalent among contact sport athletes (43.3% versus 1.2%; P < 0.01). Contact sport athletes were more likely to experience dental injuries (14.3% versus 0.0%; P < 0.01)., facial injuries (35.0% versus 6.2%; p < 0.01), and concussions (32.6% versus 2.4%; P < 0.01) relative to noncontact sport athletes. No significant difference was identified between contact and noncontact sport athletes with regards to knowledge of dental first aid.

CONCLUSIONS

Contact sport athletes are significantly more inclined to suffer dento-facial injuries and concussions relative to noncontact sport athletes. Thus, mouthguard use and knowledge of dental first aid should be particularly reinforced amongst contact sport athletes.

Injury Reduction Programs for Reducing the Incidence of Sport-Related Head and Neck Injuries Including Concussion: A Systematic Review

BACKGROUND

Sport-related head and neck injuries, including concussion, are a growing global public health concern with a need to explore injury risk reduction strategies such as neck exercises.

OBJECTIVES

To systematically review the literature to investigate: (1) the relationship between neck strength and sport-related head and neck injuries (including sport-related concussion (SRC); and (2) whether neck exercise programs can reduce the incidence of (a) sport-related head and neck injuries; and (b) SRC.

METHODS

Five databases (Ovid MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science) and research lists of included studies were searched using a combination of medical subject headings and keywords to locate original studies which reported the association between incidence of head and/or neck injury and neck strength data, or included a neck exercise intervention either in isolation or as part of a more comprehensive exercise program.

RESULTS

From an initial search of 593 studies, six were included in this review. A narrative synthesis was performed due to the heterogeneity of the included studies. The results of two observational studies reported that higher neck strength, but not deep neck flexor endurance, is associated with a lower risk of sustaining a SRC. Four intervention studies demonstrated that injury reduction programs that included neck exercises can reduce the incidence of sport-related head and neck injuries including SRC.

CONCLUSION

Consideration should be given towards incorporating neck exercises into injury reduction exercise programs to reduce the incidence of sport-related head and neck injuries, including SRC.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (registration number: 194217).

Sex-Related Differences in the Incidence, Severity, and Recovery of Concussion in Adolescent Student-Athletes Between 2009 and 2019

BACKGROUND

The sex of an athlete is thought to modulate concussion incidence; however, the effects of sex on concussion severity and recovery are less clear.

PURPOSE

To evaluate sex differences in concussion severity and recovery using a large, heterogeneous sample of young student-athletes with the goal of understanding how sex affects concussion outcomes in young athletes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The Immediate Post-Concussion Assessment and Cognitive Testing results of 11,563 baseline and 5216 postinjury tests were used to calculate the incidence of concussion of adolescent male and female student-athletes ages 12 to 22 years (median, 15 years). The postinjury tests of 3465 male and 1751 female student-athletes evaluated for concussion or head trauma were used to assess differences in the Severity Index (SI) and recovery. Chi-square tests and t tests were used to compare differences in demographic characteristics, incidence, and SI between the 2 cohorts. Multivariable linear, logistic, and Cox proportional hazards regressions were used to control for differences between cohorts in analyses of incidence, SI, and recovery.

RESULTS

When we controlled for demographic differences, female participants had higher odds of concussion (odds ratio, 1.62; 95% CI, 1.40-1.86; P < .0001) and higher SI after concussion (β = 0.67; 95% CI, 0.02-1.32; P = .04). This discrepancy in SI was a result of differences in Symptom (2.40 vs 2.94; P < .0001) and Processing Speed (0.91 vs 1.06; P = .01) composite scores between male and female participants, respectively. We found no effect of sex on time to recovery when controlling for initial concussion SI (hazard ratio, 0.94; 95% CI, 0.78-1.12; P = .48).

CONCLUSION

Using large, multisport cohorts, this study provides evidence that female athletes are at higher risk for more concussions and these concussions are more severe, but male and female athletes have similar recovery times when the analysis controls for initial concussion SI.

Purposeful Heading in Youth Soccer: A Review

Recent public concern over the short- and long-term effects of repetitive head impacts (RHI) associated with purposeful heading in soccer has led researchers to study a multitude of variables related to this important aspect of the game. Of particular interests are the effects of soccer heading in the youth population (≤ 13 years old) whose brains are undergoing rapid development. We conducted a review on youth soccer heading that includes purposeful heading frequency, head impact biomechanics, head injuries, clinical outcomes, and modifying factors. We have concluded that youth soccer players head the ball at a low frequency that typically increases with age and with a finding that boys head the ball more often than girls do. Interestingly, although girls head the ball less frequently than boys do, they tend to sustain higher head impact magnitudes. Head injuries are more likely to occur in girls versus boys and during games because of contact with another player. Clinical outcome measures of concussion are often utilized to study the effects of soccer heading, in both field and laboratory environments. Immediately following soccer heading, youth often report having a headache and demonstrate some deficits in balance measures. Modifying factors that may benefit soccer players participating in purposeful heading activities include stronger neck musculature, wearing headgear, and the use of mouthguards. Research involving youth soccer players needs to be expanded and funded appropriately to better understand the consequences of RHI in both the short and long term.

Repetitive mild traumatic brain injury affects inflammation and excitotoxic mRNA expression at acute and chronic time-points

The cumulative effect of mild traumatic brain injuries (mTBI) can result in chronic neurological damage, however the molecular mechanisms underpinning this detriment require further investigation. A closed head weight drop model that replicates the biomechanics and head acceleration forces of human mTBI was used to provide an exploration of the acute and chronic outcomes following single and repeated impacts. Adult male C57BL/6J mice were randomly assigned into one of four impact groups (control; one, five and 15 impacts) which were delivered over 23 days. Outcomes were assessed 48 hours and 3 months following the final mTBI. Hippocampal spatial learning and memory assessment revealed impaired performance in the 15-impact group compared with control in the acute phase that persisted at chronic measurement. mRNA analyses were performed on brain tissue samples of the cortex and hippocampus using quantitative RT-PCR. Eight genes were assessed, namely MAPT, GFAP, AIF1, GRIA1, CCL11, TARDBP, TNF, and NEFL, with expression changes observed based on location and follow-up duration. The cortex and hippocampus showed vulnerability to insult, displaying upregulation of key excitotoxicity and inflammation genes. Serum samples showed no difference between groups for proteins phosphorylated tau and GFAP. These data suggest that the cumulative effect of the impacts was sufficient to induce mTBI pathophysiology and clinical features. The genes investigated in this study provide opportunity for further investigation of mTBI-related neuropathology and may provide targets in the development of therapies that help mitigate the effects of mTBI.

Epidemiology of Sports-Related Injuries and Associated Risk Factors in Adolescent Athletes: An Injury Surveillance

The present study aimed to determine the epidemiology of sport-related injuries in amateur and professional adolescent athletes and the incidence of different risk factors on those injuries. Four hundred ninety-eight athletes aged 14 to 21 voluntarily participated in this prospective injury surveillance, conducted from 1 January 2019 to 31 December 2019. The information collected included: personal data, sports aspects, characteristics of the injuries, and lifestyle. Forty point four percent of the participants suffered an injury in 2019 (39% of them in a previously injured area). The average injury rate was 2.64 per 1000 h. Soccer presented the highest rate (7.21). The most common injuries were: lumbar muscle strains (12.24%), ankle sprains (11.98%), and bone fractures (9.31%). Ankles (36.12%), knees (19.32%), and shoulders (6.47%) concentrated the highest number of injuries. Fifty-nine point twenty-eight percent of the injuries occurred during practices, and 40.72% during competition or peri-competition. Higher injury rates were associated (in this order) with the following factors: (a) Greater number of hours of practice per week. (b) Not performing warm-ups. (c) Using inadequate sports facilities. (d) Being aged 14–17. (e) Not performing physical preparation. (f) Inappropriate training load. (g) Not performing injury-preventive activities. (h) Performing sports technique without the supervision of one sports coach. (i) Inadequate sports equipment. In conclusion, since most injury risk factors are modifiable, it is imperative to implement strategies to reduce amateur and professional adolescent athletes’ injury rates.

Epidemiology of Concussion in the National Football League, 2015-2019

BACKGROUND

Concussion in American football, and specifically the National Football League (NFL) is a major area of interest and key focus for injury prevention. Complete and accurate characterization of when, how, and to whom these injuries occur can facilitate injury reduction efforts. Existing studies of concussion in the NFL use publicly available data, potentially limiting data quality and the inferences that can be made.

HYPOTHESIS

Concussion incidence in the NFL decreased across the 2015-2019 seasons.

STUDY DESIGN

Descriptive epidemiology study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Concussion incidence, including counts, one-season risk, and rates per game and player-plays, among active NFL players from 2015 to 2019 is described by year, season, play type, and roster position.

RESULTS

A total 1302 concussions were identified from 2015 to 2019 among 1004 players. Of these, 80% occurred in NFL games. The average annual incidence of in-season game concussions changed over the study period, from 230.7 per season (2015-2017) to 177.0 per season (2018-2019); this represented a 23% decrease in game settings (P < 0.01). Practice concussions fluctuated across the years of the study from 38 to 67 per season (average = 50.8/season). There were 70.6 concussions per 100 preseason games, which was slightly higher than the regular season rate per game of 61.7. Overall, there were 790 regular season game concussions across 4,657,243 player-plays and 114,428 player-games during the 5-year study. In regular season games, the majority of concussions were sustained on running and passing plays (n = 119/season), and the highest average rate per play occurred on kickoffs (0.69/100 plays). Defensive secondary (cornerbacks, safeties, and generic defensive backs) and offensive line incurred the most concussions, and the highest rates of concussion were among tight ends and wide receivers.

CONCLUSION AND RELEVANCE

Concussions in the NFL are a key focus for player safety. Concussion reduction strategies were implemented before 2018, after which there was a sustained 2-year decrease in concussion incidence, providing a new benchmark from which to work toward further injury reduction.

A Longitudinal Observation of the Influence of Michigan Sports Concussion Law on Parents' Knowledge and Perception of Sport-Related Concussion

INTRODUCTION

In 2013, Michigan enacted legislation requiring parents and athletes to receive educational material concerning sport-related concussion (SRC). The aim of this study was to examine trends in concussion knowledge of parents from one community following implementation of Michigan's Sports Concussion Laws (MSCL).

METHODS

A convenience sample of parents of students from a suburban school district were surveyed via district email at one year and five years post MSCL implementation. Results were compared to an equivalent 33-item survey obtained prior to the law. Individual questions were compared between the three surveys using Chi-square analysis with statistical significance observed at p < 0.05.

RESULTS

A total of 381 responses were obtained from the one-year post-MSCL (1yMSCL) and 178 in the five-year post-MSCL (5yMSCL) survey. Awareness of district policy regarding concussion was significantly higher after implementation of the MSCL (i.e., 77% at 1yMSCL and 71% at 5yMSCL) compared to prior 18% pre-MSCL (p < 0.0001). Respondents to the 5yMSCL survey were also significantly more aware of medical guidelines surrounding "return to play" after SRC compared to 1yMSCL (84.8% v 78.7%, p = 0.01). At 5yMSCL, significantly more respondents agreed that head injuries could cause more brain damage to children than adults (86.5% v 78.7% at 1yMSCL, p = 0.03). Finally, most parents at both survey periods rated the concussion educational material as the most helpful information source regarding SRC.

CONCLUSIONS

Based on these results, parental knowledge awareness appears to have increased concerning awareness of medical guidelines for SRC and potential brain damage risks to children after enactment of the MSCL.