Epidemiology of sports-related concussion in seven US high school and collegiate sports

The Incidence of Sports-Related Concussion in Children and Adolescents: A Systematic Review and Meta-Analysis

BACKGROUND

Sport-related concussions (SRC) are a concern for young athletes due to the potential for long-term health problems. This systematic review and meta-analysis aimed to provide a comprehensive overview of the literature exploring SRC incidence in youth sports to understand the associated risks.

METHODS

Medline, Embase, SPORTDiscus, PsycINFO, and Web of Science databases were searched without language restrictions up to September 2024. Studies were included if they (i) reported data for calculation of SRC incidence, (ii) were a prospective cohort study, and (iii) included a sample aged ≤ 18 years. Studies that reported Athlete Exposure (AE) or Player Hours (PH) as SRC incidence data measures were included in a multi-level random-effects meta-analysis. Additional analysis explored SRC incidence based on age, sex, country, year of data collection, setting, and level of contact.

RESULTS

Of the 6474 studies reviewed for eligibility, 116 studies were accepted for a systematic review and 99 in the meta-analysis. A total of 3,025,911 participants were included in the review (59% male, 41% female); however, 41% of studies did not report sample size. The pooled incidence rate of SRC per 1000 AE was found to be 1.41 across 21 sports, and 4.36 per 1000 PH across 7 sports. The highest incidence per 1000 AE were in taekwondo, rugby union, and ice hockey, and the highest incidence per 1000 PH were in rugby 7s, rugby league, and rugby union.

CONCLUSIONS

This systematic review and meta-analysis can serve as an updated baseline for risk of concussion among youth athletes across various sports.

TRIAL REGISTRATION

This systematic review was registered on OSF Registries ( https://osf.io/v298s ).

Differing clinical characteristics among individuals with concussions sustained at work, in motor vehicle collisions, and sport

PURPOSE

To compare clinical characteristics in patients with concussions sustained by prevalent, but understudied, mechanisms (work-related concussion [WRC] and motor vehicle collision [MVC]-related concussion) to sport-related concussion (SRC).

METHODS

Retrospective review of 281 electronic medical records from an outpatient concussion clinic. Time since injury (days), duration of care (days), amount of care (number of visits), and perceived health (Short-Form 12) were collected.

RESULTS

The time between injury and clinic presentation was significantly greater in WRC and MVC-related concussion compared to SRC. These groups were also older, had a longer duration of care, required more referrals for outside clinical services, and reported worse perceived mental and physical health versus SRC.

CONCLUSION

These results suggest that clinical courses may be significantly different for individuals with SRC, WRC and MVC-related concussion, and that different management approaches and expectations may be necessary for these groups. Further research is indicated.

Incidence and Risk Factors for Sport-Related Concussion in Female Youth Athletes Participating in Contact and Collision Invasion Sports: A Systematic Review

BACKGROUND

The incidence and risk factors for sport-related concussion (SRC) associated with contact and collision invasion sports (CCIS) in female youth are unclear.

OBJECTIVES

This systematic review aimed to identify (i) the incidence of and (ii) risk factors for SRC in female youth athletes playing CCIS.

METHODS

A systematic search of PubMed, CINAHL, Embase, SPORTDiscus and ProQuest to 8 May, 2024 was conducted. Two reviewers independently screened articles against eligibility criteria and assessed risk of bias (Joanna Briggs Institute Critical Appraisal Tool). Aetiological or intervention studies reporting on SRC incidence or risk factors in female youth athletes (aged 13-19 years and under) participating in CCIS were included. Meta-analyses were conducted to explore SRC incidence and risk factors. For each meta-analysis of SRC incidence rate, sub-group analyses were conducted by sport. Where heterogeneity was above 60% for the meta-analysis of SRC risk/protective factors, sensitivity analyses were conducted.

RESULTS

The search yielded 4509 articles; 66 were included. Sport-related concussion incidence or risk factor data for nine CCIS were extracted. Pooled estimates revealed SRC incidence for female youth athletes in CCIS combined was 0.50/1000 match and practice hours (95% confidence interval [CI] 0.34-0.66). When examined by sport classification, SRC incidence in contact invasion sports was 0.12/1000 match and practice hours (95% CI 0.03-0.21), and in collision invasion sports was 2.08/1000 match and practice hours (95% CI 0.90-3.25). Sub-group analysis by individual sport revealed female youth soccer players had the highest overall SRC incidence rate (0.89/1000 match and practice hours, 95% CI - 0.19 to 1.97) amongst contact sports, and rugby union players had the highest overall SRC incidence rate (4.04/1000 match and practice hours, 95% CI 3.03-5.05) among collision sports. Forty-five studies (68%) reported SRC risk factor data, investigating 12 different potential risk factors. Female youth sustained over 7.5 times the rate of SRC in matches compared with practice (incidence rate ratio 7.52, 95% CI 6.32-8.95, p < 0.01) when competing in CCIS; however, considerable heterogeneity existed (I2 = 84.98%). When exploring potential risk factors, no significant difference was found in SRC rate between female youth lacrosse players wearing versus not wearing headgear (p = 0.07). No significant difference was found in SRC rates between female youth athletes competing in younger versus older age groups (incidence rate ratio 0.91, 95% CI 0.52-1.61, p = 0.48, I2 = 0.00%). Insufficient evidence was available to examine remaining risk factors.

CONCLUSIONS

This meta-analysis revealed SRC in female youth playing CCIS was higher than previously reported, with SRC rates higher in matches than practice. Soccer had the highest SRC incidence rate for female youth athletes competing in contact invasion sports, whilst rugby union demonstrated the highest SRC incidence rates for collision invasion sports. The results of this review should be interpreted with caution given the lack of representation from some common CCIS codes. Further research is required to examine SRC risk factors in female youth athletes participating in CCIS.

CLINICAL TRIAL REGISTRATION

OSF Registration: osf.io/s573v.

Posttraumatic stress symptoms in recovery from concussion

BACKGROUND

Previous literature suggests that lingering concussion symptoms may be influenced by psychological factors. The relationship of posttraumatic stress symptoms (PTSS) during recovery with pre-existing/injury related factors and concussion symptomology is not fully understood. Identification of factors contributing to symptoms of posttraumatic stress may provide guidance to improve treatment following concussion.

METHOD

This study included 287 participants (Male 40.42%, n = 116; Female 59.58%, n = 171) aged 13-75 years diagnosed with a recent concussion at one of the North Texas Concussion Registry (ConTex) specialty concussion clinic sites. Preinjury emotional history, injury related factors, and emotional state at time of initial evaluation were analyzed as predictors of post-traumatic stress symptoms (PCL-5) during recovery.

RESULTS

Sixty-one percent of participants endorsed at least one PTSS. Correlations were found between initial Sport Concussion Assessment Tool 5Ⓡ (SCAT5) total emotional symptom severity and screening measures for anxiety (GAD-7; r = .453, p < .001) and depression (PHQ-8; r = .550, p < .001) symptom scores. Of the measures from the initial visit included in the multiple regression model predicting severity of PTSS at follow-up (R2 = 0.554, β < .001), three measures predicted PTSS severity: initial SCAT5 total emotional symptom severity (β = 0.565, p < .001), PHQ-8 score (β =.166, p = .009), and GAD-7 score (β = 0.119, p = .044).

CONCLUSIONS

Symptoms of anxiety and depression along with specific SCAT5 emotional symptoms present at the time of initial evaluation may serve to predict overall level of PTSS and increased risk for PTSS during recovery. PTSS may be another dimension of response to injury and concussion recovery, with a large percentage of individuals endorsing at least one PTSS. Clinicians can utilize brief assessments such as the SCAT5 at the time of initial clinical evaluation to identify those at risk for PTSS following concussion.

Incidence of concussion and associated risk factors in collegiate soccer: findings from the NCAA-DoD CARE consortium

This retrospective cohort study aims to examine concussion incidence rates (IR) in collegiate soccer players and compare IRs based on risk factors including sex, competition level, games/practices, history of concussion, and playing position. Collegiate soccer players were recruited (n = 2,471) from 23 institutions from the NCAA-DoD Concussion Assessment, Research, and Education (CARE) Consortium. Incidence rates for concussion per 1000 athlete exposures (AEs) were calculated across the 2015-16/2016-17 seasons. Incidence rates (IR) comparing risk factor groups were also calculated. A total of 162 concussions occurred during the study, for an IR of 0.08/1000 AEs. Females were more likely to have a concussion than males overall (IR = 1.47) and were more likely to have a concussion in games (IR = 1.42) and practices (IR = 2.91). Concussions were more likely during competition compared to practice (IR = 2.53), and less likely in Division III, compared to Divisions I and II, χ2 = 6.5, p > .05. In the concussed group, male sex was associated with 2.47 times higher odds of playing defender and 2.29 times higher odds of a collision mechanism. Results confirm previous findings that females and game exposures have higher concussion IR than males and practice exposures. Findings also supported sex differences in IRs based on exposure type, position, and mechanism.

Nominal Differences in Acute Symptom Presentation and Recovery Duration of Sport-Related Concussion Between Male and Female Collegiate Athletes in the PAC-12

BACKGROUND

Sport-related concussion (SRC) is a heterogenous injury that often presents with varied symptoms and impairment. Recently, research has focused on identifying subtypes, or clinical profiles of concussion to be used in assessing and treating athletes with SRC. The purpose of this study was to investigate sex differences in clinical profiles, recovery duration, and initial symptom severity after SRC in a cohort of collegiate athletes in the Pacific-12 Conference (Pac-12).

METHODS

This prospective cohort study examined post-SRC symptoms, recovery, and return-to-play times using data from the Pac-12 CARE Affiliated Program and Pac-12 Health Analytics Program. Clinical profiles reported by student-athletes were defined by the number (> 50%) of specific symptoms frequently reported for each profile. Generalized linear mixed models were used to examine associations among sex, clinical profiles, time-to-recovery, and return-to-play times.

RESULTS

479 concussion incidents met inclusion criteria. The probabilities of initial presentation of each clinical profile, initial injury severity scores, and recovery times within a profile did not differ between sexes (p = 0.33-0.98). However, both males and females had > 0.75 probabilities of exhibiting cognitive and ocular profiles. Initial injury severity score was a strong nonlinear predictor of initial number of clinical profiles (p < 0.0001), which did not differ between sexes. The number of clinical profiles was also a nonlinear predictor of time-to-recovery (p = 0.03) and return-to-play times (p < 0.0001).

CONCLUSIONS

Initial symptom severity was strongly predictive of the number of acute clinical profiles experienced post-SRC. As the number of clinical profiles increased, time-to-recovery and time to return-to-play also increased. Factors other than sex may be better associated with acute symptom presentation post-concussion as no sex differences were found in reported clinical profiles or recovery. Understanding the number and type of clinical profiles experienced post-SRC may help inform concussion diagnostics and management.

Awareness and understanding of concussion among Aboriginal Australians with high health literacy

Aim

Indigenous Australians have higher rates of traumatic brain injury, with 74-90% of such injuries being concussion. This study explores concussion awareness and knowledge in Aboriginal Western Australians with high health literacy.

Materials & methods

Participants, aged 18-65 years, engaged in research topic yarning, and thematic analysis of the qualitative data then undertaken.

Results

There was awareness that direct head trauma can result in concussion, but a lack of differentiation between concussion and other head injuries. Knowledge was gained from sport, media or lived-experience. Symptom minimization and diversity of concussion symptoms prevented participants from seeking medical treatment. This was exacerbated by a mistrust of the medical system.

Conclusion

Research findings highlight knowledge and service gaps where co-designed strategies can be targeted.

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.

Specialist healthcare services for concussion/mild traumatic brain injury in England: a consensus statement using modified Delphi methodology

OBJECTIVE

To establish a consensus on the structure and process of healthcare services for patients with concussion in England to facilitate better healthcare quality and patient outcome.

DESIGN

This consensus study followed the modified Delphi methodology with five phases: participant identification, item development, two rounds of voting and a meeting to finalise the consensus statements. The predefined threshold for agreement was set at ≥70%.

SETTING

Specialist outpatient services.

PARTICIPANTS

Members of the UK Head Injury Network were invited to participate. The network consists of clinical specialists in head injury practising in emergency medicine, neurology, neuropsychology, neurosurgery, paediatric medicine, rehabilitation medicine and sports and exercise medicine in England.

PRIMARY OUTCOME MEASURE

A consensus statement on the structure and process of specialist outpatient care for patients with concussion in England.

RESULTS

55 items were voted on in the first round. 29 items were removed following the first voting round and 3 items were removed following the second voting round. Items were modified where appropriate. A final 18 statements reached consensus covering 3 main topics in specialist healthcare services for concussion; care pathway to structured follow-up, prognosis and measures of recovery, and provision of outpatient clinics.

CONCLUSIONS

This work presents statements on how the healthcare services for patients with concussion in England could be redesigned to meet their health needs. Future work will seek to implement these into the clinical pathway.

A Common Data Element-Based Adjudication Process for mTBI Clinical Profiles: A Targeted Multidomain Clinical Trial Preliminary Study

INTRODUCTION

The primary purpose of this study was to examine the prevalence and percent agreement of clinician-identified mild traumatic brain injury (mTBI) clinical profiles and cutoff scores for selected Federal Interagency Traumatic Brain Injury Research common data elements (CDEs). A secondary purpose was to investigate the predictive value of established CDE assessments in determining clinical profiles in adults with mTBI.

MATERIALS AND METHODS

Seventy-one (23 males; 48 females) participants (M = 29.00, SD = 7.60, range 18-48 years) within 1-5 months (M = 24.20, SD = 25.30, range 8-154 days) of mTBI completed a clinical interview/exam and a multidomain assessment conducted by a licensed clinician with specialized training in concussion, and this information was used to identify mTBI clinical profile(s). A researcher administered CDE assessments to all participants, and scores exceeding CDE cutoffs were used to identify an mTBI clinical profile. The clinician- and CDE-identified clinical profiles were submitted to a multidisciplinary team for adjudication. The prevalence and percent agreement between clinician- and CDE-identified clinical profiles was documented, and a series of logistic regressions with adjusted odds ratios were performed to identify which CDE assessments best predicted clinician-identified mTBI clinical profiles.

RESULTS

Migraine/headache, vestibular, and anxiety/mood mTBI clinical profiles exhibited the highest prevalence and overall percent agreement among CDE and clinician approaches. Participants exceeding cutoff scores for the Global Severity Index and Headache Impact Test-6 assessments were 3.90 and 8.81 times more likely to have anxiety/mood and migraine/headache profiles, respectively. The Vestibular/Ocular Motor Screening vestibular items and the Pittsburgh Sleep Quality Index total score were predictive of clinician-identified vestibular and sleep profiles, respectively.

CONCLUSIONS

The CDEs from migraine/headache, vestibular, and anxiety/mood domains, and to a lesser extent the sleep modifier, may be clinically useful for identifying patients with these profiles following mTBI. However, CDEs for cognitive and ocular may have more limited clinical value for identifying mTBI profiles.

Factors That Impact the Long-Term Outcome of Postconcussive Dizziness Among Post-9/11 Veterans

PURPOSE

The primary aim of this study was to examine the factors associated with long-term outcomes of postconcussive disruptive dizziness in Veterans of the post-9/11 wars.

METHOD

For this observational cohort study, the Neurobehavioral Symptom Inventory-Vestibular subscale (NSI-V) score was used as an outcome measure for dizziness in 987 post-9/11 Veterans who indicated disruptive dizziness at an initial Veterans Health Administration Comprehensive Traumatic Brain Injury Evaluation (CTBIE). An NSI-V change score was calculated as the difference in the scores obtained at the initial CTBIE and on a subsequent survey. Differences in the NSI-V change scores were examined for demographics, injury characteristics, comorbidities, and vestibular and balance function variables, and multiple linear regression analyses were used to explore associations among the variables and the NSI-V change score.

RESULTS

The majority of Veterans (61%) demonstrated a decrease in the NSI-V score, suggesting less dizziness on the survey compared with the CTBIE; 16% showed no change; and 22% had a higher score. Significant differences in the NSI-V change score were observed for traumatic brain injury (TBI) status, diagnoses of post-traumatic stress disorder (PTSD), headache and insomnia, and vestibular function. Multivariate regressions revealed significant associations between the NSI-V change score and the initial CTBIE NSI-V score, education level, race/ethnicity, TBI status, diagnoses of PTSD or hearing loss, and vestibular function.

CONCLUSIONS

Postconcussive dizziness can continue for years following an injury. Factors associated with poor prognosis include TBI, diagnoses of PTSD or hearing loss, abnormal vestibular function, increased age, identification as a Black Veteran, and high school education level.

The Toronto Concussion Study: a prospective investigation of characteristics in a cohort of adults from the general population seeking care following acute concussion, 2016-2020

Purpose

There is limited research regarding the characteristics of those from the general population who seek care following acute concussion.

Methods

To address this gap, a large cohort of 473 adults diagnosed with an acute concussion (female participants = 287; male participants = 186) was followed using objective measures prospectively over 16 weeks beginning at a mean of 5.1 days post-injury.

Results

Falls were the most common mechanism of injury (MOI) (n = 137, 29.0%), followed by sports-related recreation (n = 119, 25.2%). Male participants were more likely to be injured playing recreational sports or in a violence-related incident; female participants were more likely to be injured by falling. Post-traumatic amnesia (PTA) was reported by 80 participants (16.9 %), and loss of consciousness (LOC) was reported by 110 (23.3%). In total, 54 participants (11.4%) reported both PTA and LOC. Male participants had significantly higher rates of PTA and LOC after their injury compared to their female counterparts. Higher initial symptom burden was associated with a longer duration of recovery for both male and female participants. Female participants had more symptoms and higher severity of symptoms at presentation compared to male participants. Female participants were identified to have a longer recovery duration, with a mean survival time of 6.50 weeks compared to 5.45 weeks in male participants (p < 0.0001). A relatively high proportion of female and male participants in this study reported premorbid diagnoses of depression and anxiety compared to general population characteristics.

Conclusion

Although premorbid diagnoses of depression and/or anxiety were associated with higher symptom burden at the initial visit, the duration of symptoms was not directly associated with a pre-injury history of psychological/psychiatric disturbance. This cohort of adults, from the general population, seeking care for their acute concussion attained clinical and functional recovery over a period of 4-12 weeks.

Quantifying head impact exposure, mechanisms and kinematics using instrumented mouthguards in female high school lacrosse

Current debate exists regarding the need for protective headwear in female lacrosse. To inform this issue, the current study quantified head impact exposure, mechanisms and kinematics in female lacrosse using instrumented mouthguards. A female high school varsity lacrosse team of 17 players wore the Stanford Instrumented Mouthguard (MiG) during 14 competitive games. Video footage was reviewed to remove false-positive recordings and verify head impacts, which resulted in a rate of 0.32 head impacts per athlete-exposure. Of the 31 video-confirmed head impacts, 54.8% were identified as stick contacts, 38.7% were player contacts and 6.5% were falls. Stick contacts had the greatest peak head kinematics. The most common impact site was the side of the head (35.5%), followed by the face/jaw (25.8%), forehead (6.5%), and crown (6.5%). Impacts to the face/jaw region of the head had significantly (p < 0.05) greater peak kinematics compared to other regions of the head, which may have resulted from the interaction of the impacting surface, or the lower jaw, and the sensor. The current study provides initial data regarding the frequency, magnitude and site of impacts sustained in female high school lacrosse. A larger sample size of high quality head impact data in female lacrosse is required to confirm these findings.

A Helmet of Her Own?: A Qualitative Study of Key Stakeholder Perspectives on Headgear in Girls' Lacrosse

Introduction

Despite the high incidence rate of concussions in women's lacrosse, there is substantial push back against the use of helmets at the secondary educational and collegiate levels in the U.S. This study examines the social factors influencing the controversy surrounding the use of protective headgear and how the recent development of headgear specific to the women's game has shaped ongoing debates.

Methods

Purposeful sampling was used to recruit interviewees with research knowledge or firsthand experience with injury and protective headgear in girls' lacrosse. Semistructured interviews were conducted and subsequently coded using qualitative research software to identify key themes and patterns.

Results

Sixteen respondents participated in this study; 4 players, 4 coaches, 3 researchers, and 5 administrators were represented in this sample. Overarching themes identified across these interviews included playing through pain, health consequences of concussions, concussion prevention strategies and the potential role of headgear, symbolism of headgear, gender dynamics, autonomy, and decision making.

Conclusions

This qualitative study shows the importance of attention to the unique history of girls' lacrosse and current narratives surrounding headgear in the sport. There is a need for greater collaboration and consensus between all relevant groups to ensure that headgear best addresses the concerns of the people who will ultimately be using it. Future qualitative research should build on this preliminary study with a larger and more diverse sample to follow up on key themes and ultimately inform effective safety measures to protect athletes.

Refinement of saliva microRNA biomarkers for sports-related concussion

BACKGROUND

Recognizing sport-related concussion (SRC) is challenging and relies heavily on subjective symptom reports. An objective, biological marker could improve recognition and understanding of SRC. There is emerging evidence that salivary micro-ribonucleic acids (miRNAs) may serve as biomarkers of concussion; however, it remains unclear whether concussion-related miRNAs are impacted by exercise. We sought to determine whether 40 miRNAs previously implicated in concussion pathophysiology were affected by participation in a variety of contact and non-contact sports. Our goal was to refine a miRNA-based tool capable of identifying athletes with SRC without the confounding effects of exercise.

METHODS

This case-control study harmonized data from concussed and non-concussed athletes recruited across 10 sites. Levels of salivary miRNAs within 455 samples from 314 individuals were measured with RNA sequencing. Within-subjects testing was used to identify and exclude miRNAs that changed with either (a) a single episode of exercise (166 samples from 83 individuals) or (b) season-long participation in contact sports (212 samples from 106 individuals). The miRNAs that were not impacted by exercise were interrogated for SRC diagnostic utility using logistic regression (172 samples from 75 concussed and 97 non-concussed individuals).

RESULTS

Two miRNAs (miR-532-5p and miR-182-5p) decreased (adjusted p < 0.05) after a single episode of exercise, and 1 miRNA (miR-4510) increased only after contact sports participation. Twenty-three miRNAs changed at the end of a contact sports season. Two of these miRNAs (miR-26b-3p and miR-29c-3p) were associated (R > 0.50; adjusted p < 0.05) with the number of head impacts sustained in a single football practice. Among the 15 miRNAs not confounded by exercise or season-long contact sports participation, 11 demonstrated a significant difference (adjusted p < 0.05) between concussed and non-concussed participants, and 6 displayed moderate ability (area under curve > 0.70) to identify concussion. A single ratio (miR-27a-5p/miR-30a-3p) displayed the highest accuracy (AUC = 0.810, sensitivity = 82.4%, specificity = 73.3%) for differentiating concussed and non-concussed participants. Accuracy did not differ between participants with SRC and non-SRC (z = 0.5, p = 0.60).

CONCLUSION

Salivary miRNA levels may accurately identify SRC when not confounded by exercise. Refinement of this approach in a large cohort of athletes could eventually lead to a non-invasive, sideline adjunct for SRC assessment.

Incidence of injuries among lacrosse athletes: a systematic review and meta-analysis

OBJECTIVES

The purpose of this systematic review was to determine the incidence of injuries among lacrosse athletes and the differences in rates of injury by location and gender.

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were implemented to conduct this systematic review.[1] The following variables were extracted from each of the included articles: location of injury, gender of patient, and incidence of injury among study population. The methodological quality of the included studies was assessed using mixed-methods appraisal tool (MMAT) version 2018.[2] Estimated rates were reported as pooled proportion with 95% CI. Rates of injury were calculated as a rate per 1000 athletic exposures (AEs), defined as an athlete participating in 1 practice or competition in which he or she was exposed to the possibility of athletic injury.

RESULTS

This study found that the highest injury rate among lacrosse athletes was to the lower leg/ankle/foot with a rate of 0.66 injuries per 1000 AEs (95% CI, 0.51, 0.82). This injury pattern was also found to be the highest among both male and female lacrosse athletes. No statistical significance was detected when comparing rates of injury across gender, regardless of location. The injury pattern with the lowest rates of injury for female athletes being to the shoulder/clavicle and the neck for male athletes.

CONCLUSION

The highest rate of injury among lacrosse athletes was to the lower leg/ankle/foot. As participation in lacrosse continues to rise, there is a greater need for understanding the rate of injury and injury characteristics for physicians and trainers to provide effective care to lacrosse athletes.

Higher rates of concussion following COVID-19 infection in high school athletes

OBJECTIVE

To compare concussion rates (CRs) over one academic year in high school athletes with and without a COVID-19 infection prior to concussion.

METHODS

Illness and concussion were prospectively reported for male and female high school athletes across six states over one academic year in the Players Health Rehab surveillance system. Concussion was truncated to 60 days following recovery and return to sport from COVID-19. CRs were estimated per 1000 athletes per academic year and stratified by those who tested positive for COVID-19 infection (with COVID-19) and those who did not (no COVID-19). Poisson regression analyses estimated rate ratio (RR) of concussion controlling for state, gender and an offset of the log athlete participation (with COVID-19 and no COVID-19).

RESULTS

Of 72 522 athletes, 430 COVID-19 infections and 1273 concussions were reported. The CR was greater in athletes who reported COVID-19 (CR=74.4/1000 athletes/year, 95% CI 49.6 to 99.3) compared with those who did not (CR=17.2, 95% CI 16.3 to 18.2). Athletes with recent COVID-19 had a threefold higher rate of concussion (RR=3.1, 95% CI 2.0 to 4.7).

CONCLUSION

Athletes returning from COVID-19 had higher CRs than those who did not experience COVID-19. This may be related to ongoing COVID-19 sequelae or deconditioning related to reduced training and competition load during the illness and when returning to sport. Further research is needed to understand the association of recent COVID-19 infection and concussion in order to inform preventive strategies.

Associations between interpersonal violence victimisation and concussions among US college students

Interpersonal violence is common on college campuses and is associated with many adverse health outcomes; however, it remains unknown whether experiencing interpersonal violence victimisation is associated with concussions. The aim of this study was to estimate the associations between interpersonal violence, including emotional abuse, physical abuse and sexual assault, and concussions among a large, diverse sample of college students. We analysed cross-sectional data from the 2018-2019 national (US) Healthy Minds Study (N = 1,478). Multiple logistic regression analyses were conducted to estimate the association between interpersonal violence victimisation (any violence victimisation, emotional abuse, physical abuse and sexual assault) and concussion history (any concussion, diagnosed concussion and undiagnosed concussion), while adjusting for potential confounders. Analyses were conducted among the overall sample and separately by male and female participants. Results showed patterns of significant associations between interpersonal violence victimisation and concussions among the overall sample and among male and female participants. Among the overall sample, any interpersonal violence victimisation (adjusted odds ratio [AOR] 1.45, 95% confidence interval [CI] 1.13-1.88), emotional abuse (AOR 1.36, 95% CI 1.06-1.76), physical abuse (AOR 1.61, 95% CI 1.07-2.44) and sexual assault (AOR 2.17, 95% CI 1.44-3.26) were associated with higher odds of any concussion history. Sexual assault victimisation had the strongest association with any concussion history among male (AOR 1.96, 95% CI 1.04-3.71) and female (AOR 2.96, 95% CI 1.62-5.43) participants. These results expand on prior interpersonal violence and concussion research by showing an association with multiple victimisation measures among a large and diverse sample of college students. Medical professionals should screen for concussions among college students who experience emotional abuse, physical abuse and sexual assault to provide appropriate guidance. Information on the symptoms of concussions should be incorporated into campus violence awareness and prevention efforts.

"You Can't Fix Your Brain": Exploring concussion experiences of children and parents

PURPOSE

To explore the experiences, information needs and preferences of children who have had a concussion and their parents who have cared for them.

DESIGN

Qualitative description.

METHODS

Semi-structured qualitative interviews were conducted via Zoom with children who have had a concussion between ages 5 and 16 years and parents who have cared for a child with a concussion. Interviews were audio-recorded and transcribed.

RESULTS

Fourteen interviews were conducted with children and parents who have experiences with concussion. Four major themes were identified: (1) mechanism of injury and concussion symptoms experienced by children, (2) parent concerns, emotions, and health care experience with child's concussion, (3) concussions affect more than just your head and, (4) health information seeking, and preferences of parents and children related to concussion. Children and their parents have unique experiences, information needs and preferences regarding concussion.

PRACTICE IMPLICATIONS

This information offers valuable insights about developing resources about childhood concussion that parents and children will find useful and relevant. This research has direct relevance to healthcare professionals who may encounter children with concussion in their daily practice so they can ensure the needs of children and families are being met. Our findings will be used to create the content for an innovative knowledge translation tool about pediatric concussion.

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.

Participation in Collision Sports and Cognitive Aging Among Swedish Twins

We examined the association between early-life participation in collision sports and later-life cognitive health over a 28-year period in a population-based sample drawn from the longitudinal Swedish Adoption/Twin Study of Aging (1987-2014). Cognitive measures included the Mini-Mental State Examination and performance across multiple cognitive domains (e.g., global cognition, verbal ability, spatial ability, memory, processing speed). Among a sample of 660 adults (mean age at baseline, 62.8 years (range: 50-88); 58.2% female), who contributed 10,944 person-years of follow-up, there were 450 cases of cognitive impairment (crude rate = 41.1/1,000 person-years). Early-life participation in collision sports was not significantly associated with cognitive impairment at baseline or with its onset over a 28-year period in a time-to-event analysis, which accounted for the semi-competing risk of death. Furthermore, growth curve models revealed no association between early-life participation in collision sports and the level of or change in trajectories of cognition across multiple domains overall or in sex-stratified models. We discuss the long-term implications of adolescent participation in collision sports on cognitive health.

Clinical Assessment of Concussion and Persistent Post-Concussive Symptoms for Neurologists

PURPOSE OF REVIEW

Concussion produces a variety of signs and symptoms. Most patients recover within 2-4 weeks, but a significant minority experiences persistent post-concussive symptoms (PPCS), some of which may be from associated cervical or persistent neurologic sub-system (e.g., vestibular) dysfunction. This review provides evidence-based information for a pertinent history and physical examination of patients with concussion.

RECENT FINDINGS

The differential diagnosis of PPCS is based on the mechanism of injury, a thorough medical history and concussion-pertinent neurological and cervical physical examinations. The concussion physical examination focuses on elements of autonomic function, oculomotor and vestibular function, and the cervical spine. Abnormalities identified on physical examination can inform specific forms of rehabilitation to help speed recovery. Emerging data show that there are specific symptom generators after concussion that can be identified by a thorough history, a pertinent physical examination, and adjunct tests when indicated.

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.

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.

Associations between concussion and risk of diagnosis of psychological and neurological disorders: a retrospective population-based cohort study

Objective

To investigate associations between concussion and the risk of follow-up diagnoses of attention-deficit hyperactivity disorder (ADHD), mood and anxiety disorders (MADs), dementia and Parkinson’s disease.

Design

A retrospective population-based cohort study.

Setting

Administrative health data for the Province of Manitoba between 1990–1991 and 2014–2015.

Participants

A total of 47 483 individuals were diagnosed with a concussion using International Classification of Diseases (ICD) codes (ICD-9-CM: 850; ICD-10-CA: S06.0). All concussed subjects were matched with healthy controls at a 3:1 ratio based on age, sex and geographical location. Associations between concussion and conditions of interest diagnosed later in life were assessed using a stratified Cox proportional hazards regression model, with adjustments for socioeconomic status and pre-existing medical conditions.

Results

28 021 men (mean age ±SD, 25±18 years) and 19 462 women (30±21 years) were included in the concussion group, while 81 871 men (25±18 years) and 57 159 women (30±21 years) were included in the matched control group. Concussion was associated with adjusted hazard ratios of 1.39 (95% CI 1.32 to 1.46, p<0.001) for ADHD, 1.72 (95% CI 1.69 to 1.76; p<0.001) for MADs, 1.72 (95% CI 1.61 to 1.84; p<0.001) for dementia and 1.57 (95% CI 1.41 to 1.75; p<0.001) for Parkinson’s disease.

Conclusion

Concussion was associated with an increased risk of diagnosis for all four conditions of interest later in life.

Head Impact Telemetry System's Video-based Impact Detection and Location Accuracy

PURPOSE

This study aimed to quantify the Head Impact Telemetry (HIT) System's impact detection and location measurement accuracy using an impact biomechanics data set paired with video of high school football special teams plays.

METHODS

The head impact biomechanics data set and video were collected from 22 high school football players, wearing HIT System instrumented helmets, competing in 218 special teams plays over a single high school football season. We used two separate video analysis approaches. To quantify the impact detection accuracy, we evaluated the video for head impacts independently of the impact data collection triggers collected by the HIT System. Video-observed impacts matched to valid and invalid head impacts by the HIT System algorithm were categorized as true positives, false positives, false negatives, and true negatives. To quantify impact location accuracy, we analyzed video-synchronized head impacts for impact location independent of the HIT System's impact location measurement and quantified the estimated percent agreement of impact location between the HIT System recorded impact location and the impact location observed on video.

RESULTS

The HIT System's impact-filtering algorithm had 69% sensitivity, 72% specificity, and 70% accuracy in categorizing true and non-head impact data collection triggers. The HIT System agreed with video-observed impact locations on 64% of the 129 impacts we analyzed (unweighted k = 0.43, 95% confidence interval = 0.31-0.54).

CONCLUSION

This work provides data on the HIT System's impact detection and location accuracy during high school football special teams plays using game video analysis that has not been previously published. Based on our data, we believe that the HIT System is useful for estimating population-based impact location distributions for special teams plays.

Heads Up Football Training Decreases Concussion Rates in High School Football Players

OBJECTIVE

The objective of this study was to determine whether football players receiving heads up (HU) training would display a lower rate of sport-related concussion (SRC) compared to those without HU training.

DESIGN

Prospective cohort.

SETTING

Scholastic football fields.

PATIENTS

Two thousand five hundred fourteen scholastic football players during the 2015 to 2016 football season were monitored throughout the football season.

INTERVENTIONS

Before the preseason, 1 coach from 14 schools received HU training from US football. These schools were matched with 10 control schools performing standard football training [non-heads up (NHU)]. Random monitoring for proper coaching instruction was performed during the season. School athletic trainers monitored injuries and return to sport over the season for all schools.

MAIN OUTCOME MEASURES

The outcome measures of concussions and associated time loss were determined before data collection began. Injury incidence and rate ratios were calculated to determine program effectiveness.

RESULTS

During the season, football players sustained 117 concussions (HU = 75; NHU = 42). The HU players displayed a significantly lower concussion rate (4.1 vs 6.0/100 players) compared with NHU teams [rate ratio = 1.5; 95% confidence interval (CI), 1.1-5.4]. The HU group returned to full participation 27% faster than athletes in the NHU group [time loss: 18.2 days (95% CI, 15.8-20.6) vs 24.8 days (95% CI, 19.9-29.7)], respectively.

CONCLUSIONS

This is the first study to evaluate the impact of the HU program on the incidence of SRC in high school football players. Our data demonstrated that the HU program reduced SRC rates by 33% supporting the use of US HU football training as an effective method to decrease the rate of SRCs in scholastic football.

CLINICAL RELEVANCE

This study is the first to prospectively explore the effect of HU training on the incidence and recovery from SRC in high school football players.

Symptom Burden, School Function, and Physical Activity One Year Following Pediatric Concussion

OBJECTIVES

To characterize symptom burden, school function, and physical activity in youth 1 year following acute concussion and those with subsequent repeat concussion.

STUDY DESIGN

Secondary analysis of Predicting Persistent Postconcussive Problems in Pediatrics prospective, multicenter cohort study conducted in 9 Canadian emergency departments. Participants were children between ages 5 and 18 years who presented consecutively ≤48 hours of concussion and agreed to participate in a post hoc electronic survey 1 year after injury. Outcomes were assessed using a standardized 25-question symptom scale derived from the Post-Concussion Symptom Inventory-Parent; school function and physical activity outcomes were queried. The primary outcome was total symptom score 1 year following concussion, defined as the number of symptoms experienced more than before injury.

RESULTS

Of 3052 youth enrolled in the Predicting Persistent Postconcussive Problems in Pediatrics study, 432 (median [IQR] age, 11.5 [9,14] years; 266 [62%] male) completed the 1-year survey; 34 respondents reported a repeat concussion. Following acute concussion, youth were more likely to be symptom-free than following repeat concussion (75% vs 50%; difference = 25% [95% CI 8-41]; P = .002) and to have recovered fully (90% vs 74%; difference = 17% [95% CI 5-34]; P = .002) after 1 year. Although physical symptoms were less 1 year after initial emergency department presentation for both groups (P < .001), youth with a repeat concussion reported greater headache persistence (26% vs 13%; difference = 13% [95% CI 1,31]; P = .024). Both groups returned to their normal school routine (100% vs 95%; difference = 5% [95% CI -5 to 8; P = .618). Youth without repeat concussion more frequently returned to normal physical activities (98% vs 85%; difference = 13% [95% CI 4-28]; P < .0001) and sport (95% vs 82%; difference = 13% [95% CI 3-29]; P = .009).

CONCLUSIONS

Most youth are symptom-free and fully recovered 1 year following concussion. Some children with repeat concussion have worse outcomes and have delays in returning to normal school routines and sport.

Epidemiology of Sport-Related Concussion

Sport-related concussions are common in the United States. Concussion rates have increased over time, likely due to improved recognition and awareness. Concussion rates vary across level (high school vs college), sex, and sport. Concussion rates are the highest among men, particularly in football, wrestling, ice hockey, and lacrosse where collisions and contact are inherent to the sports, although girls'/women's soccer rates are high. In gender-comparable sports, women have higher concussion rates. Continued data collection will increase understanding of sport-related concussion and provide areas for targeted prevention in the future.

One season of head-to-ball impact exposure alters functional connectivity in a central autonomic network

Repetitive head impacts represent a risk factor for neurological impairment in team-sport athletes. In the absence of symptoms, a physiological basis for acute injury has not been elucidated. A basic brain function that is disrupted after mild traumatic brain injury is the regulation of homeostasis, instantiated by activity across a specific set of brain regions that comprise a central autonomic network. We sought to relate head-to-ball impact exposure to changes in functional connectivity in a core set of central autonomic regions and then to determine the relation between changes in brain and changes in behavior, specifically cognitive control. Thirteen collegiate men's soccer players and eleven control athletes (golf, cross-country) underwent resting-state fMRI and behavioral testing before and after the season, and a core group of cortical, subcortical, and brainstem regions was selected to represent the central autonomic network. Head-to-ball impacts were recorded for each soccer player. Cognitive control was assessed using a Dot Probe Expectancy task. We observed that head-to-ball impact exposure was associated with diffuse increases in functional connectivity across a core CAN subnetwork. Increased functional connectivity between the left insula and left medial orbitofrontal cortex was associated with diminished proactive cognitive control after the season in those sustaining the greatest number of head-to-ball impacts. These findings encourage measures of autonomic physiology to monitor brain health in contact and collision sport athletes.

Parent-Child Agreement on Postconcussion Symptoms in the Acute Postinjury Period

OBJECTIVES

To evaluate parent-child agreement on postconcussion symptom severity within 48 hours of injury and examine the comparative predictive power of a clinical prediction rule when using parent or child symptom reporting.

METHODS

Both patients and parents quantified preinjury and current symptoms using the Postconcussion Symptom Inventory (PCSI) in the pediatric emergency department. Two-way mixed, absolute measure intraclass correlation coefficients were calculated to evaluate the agreement between patient and parent reports. A multiple logistic regression was run with 9 items to determine the predictive power of the Predicting and Preventing Postconcussive Problems in Pediatrics clinical prediction rule when using the child-reported PCSI. Delong's receiver operating characteristic curve analysis was used to compare the area under the curve (AUC) for the child-report models versus previously published parent-report models.

RESULTS

Overall parent-child agreement for the total PCSI score was fair (intraclass correlation coefficient = 0.66). Parent-child agreement was greater for (1) postinjury (versus preinjury) ratings, (2) physical (versus emotional) symptoms, and (3) older (versus younger) children. Applying the clinical prediction rule by using the child-reported PCSI maintained similar predictive power to parent-reported PCSI (child AUC = 0.70 [95% confidence interval: 0.67-0.72]; parent AUC = 0.71 [95% confidence interval: 0.68-0.74]; P = .23).

CONCLUSIONS

Overall parent-child agreement on postconcussion symptoms is fair but varies according to several factors. The findings for physical symptoms and the clinical prediction rule have high agreement; information in these domains are likely to be similar regardless of whether they are provided by either the parent or child. Younger children and emotional symptoms show poorer agreement; interviewing both the child and the parent would provide more comprehensive information in these instances.

Exploring the association between recent concussion, subconcussive impacts and depressive symptoms in male Australian Football players

Objectives

To explore the association between depressive symptoms and recent head-related trauma (diagnosed concussion, subconcussive impacts) in semiprofessional male Australian Football (AF) players.

Methods

Sixty-nine semiprofessional male players from a West Australian Football League (WAFL) club participated in the study (M_age=21.81, SD=2.91 years). Depressive symptoms were measured using the Centre for Epidemiological Studies Depression Scale. Injuries and potential confounding variables (eg, pre-existing mental health condition; alcohol or drug hangovers; experiencing a stressful event) were self-reported anonymously using the WAFL Injury Report Survey. Both tools were administered every 2-weeks over the first 22-weeks of the WAFL season. Controlling for potential confounding variables and other injuries, a repeated measures generalised estimating equations model assessed the risk of clinically relevant depressive symptoms occurring, when diagnosed concussion or subconcussive impacts were experienced.

Results

A total of 10 concussions and 183 subconcussive impacts were reported. Players who experienced a concussion were almost nine times more likely to experience clinically relevant depressive symptoms (OR 8.88, 95% CI 2.65 to 29.77, p<0.001). Although elevated, depressive symptoms following subconcussive impacts were not statistically significant (OR 1.13, 95% CI 0.67 to 1.92, p=0.641).

Conclusion

These findings indicate that semiprofessional AF athletes may be at risk of experiencing depressive symptoms after concussion. Severity (concussion vs subconcussive impacts) and dose (number of impacts) appear to have an important relationship with depressive symptom outcomes in this cohort and should be considered for further research and management of player welfare.

An Examination of 4 Questions Assessing Self-reported Concussions Among High School Students Participating in Team Sports

OBJECTIVE

Current prevalence estimates of youth sports-related concussions are inconsistent because of variation in methodology and potentially unreported concussions.

METHODS

In 2013, Connecticut, Ohio, and Utah each added different questions that assessed self-reported concussions to the Youth Risk Behavior Survey. Two questions referenced recognition of a concussion by the student, 1 referenced identification by a doctor, and 1 referenced suspicion by a coach. Chi-square analyses were used to identify whether there was an association between demographic characteristics and the concussion questions among high school students who played on at least 1 sports team.

RESULTS

The percentage of students who reported concussions ranged from 17.6% to 20.1%.

CONCLUSIONS

These estimates are higher than rates of concussions diagnosed in emergency departments or reported by athletic trainers but were similar across the 4 questions. The field would benefit from a better understanding of the impact of question wording and format on estimates of concussion prevalence.

The North Texas Concussion Registry (ConTex)

PURPOSE

The North Texas Concussion Registry (ConTex) was established in 2015 as a multi-institutional collaboration intended to study risk factors, recovery patterns and clinical outcomes associated with concussion across the lifespan, with a particular emphasis on sport-related concussion.

PARTICIPANTS

Prospective enrolment of individuals who sustained a concussion within the past 6 months who were seen at one of four North Texas ConTex concussion clinics which employ common diagnostic criteria and assessment metrics to evaluate effects of a concussion as well as longitudinal tracking of recovery.

FINDINGS TO DATE

The ConTex database and multidisciplinary oversight team has been established, and over 1700 participants aged 5-88 years have been enrolled. A majority of concussions were sport-related (60%), with a mean age of 17.5 years and similar numbers of males and females. Three-month follow-up compliance has been excellent (86%), with a majority of subjects reporting good recovery by that time. ConTex has provided a rich data source for multiple research projects focused on concussion characteristics, risk factors and outcomes, and led to the development of a statewide youth concussion registry.

FUTURE PLANS

ConTex data are being analysed to add to the body of knowledge regarding concussion mechanisms, factors related to recovery and improving outcomes for concussion patients. ConTex will serve as a platform for future treatment studies and may serve as a model for other concussion surveillance programmes.

Adapting the Dynamic, Recursive Model of Sport Injury to Concussion: An Individualized Approach to Concussion Prevention, Detection, Assessment, and Treatment

The risk factors of concussion may be categorized as intrinsic (internal factors specific to the individual) or extrinsic (external factors related to the environment or sport). Identifying these factors is part of an individualized, patient-centered approach to prevention, assessment, and management of concussion. In most cases, the symptoms of concussion resolve in the initial few days following the injury, and a strategy involving a gradual return to sport and school is recommended. When symptoms persist for longer than 7 to 10 days, a multifaceted interdisciplinary assessment to guide treatment is recommended. This article applies the dynamic, recursive model of sport injury to sport-related concussion and summarizes the process of individualized assessment and management following concussion in athletes of all ages, with a focus on physical rehabilitation. J Orthop Sports Phys Ther 2019;49(11):799-810. doi:10.2519/jospt.2019.8926.

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Girls' Lacrosse (2008-2009 Through 2013-2014) and National Collegiate Athletic Association Women's Lacrosse (2004-2005 Through 2013-2014)

CONTEXT

The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online (HS RIO) system and the National Collegiate Athletic Association Injury Surveillance Program (NCAA-ISP) has aided the acquisition of girls' and women's lacrosse injury data.

OBJECTIVE

To describe the epidemiology of injuries sustained in high school girls' lacrosse in the 2008-2009 through 2013-2014 academic years and collegiate women's lacrosse in the 2004-2005 through 2013-2014-academic years using Web-based sports injury surveillance.

DESIGN

Descriptive epidemiology study.

SETTING

Online injury surveillance from high school girls' (annual average = 55) and collegiate women's (annual average = 19) lacrosse teams.

PATIENTS OR OTHER PARTICIPANTS

Female lacrosse players who participated in practices or competitions during the 2008-2009 through 2013-2014 academic years for high school or the 2004-2005 through 2013-2014 academic years for college.

MAIN OUTCOME MEASURE(S)

Athletic trainers collected time-loss injury (≥24 hours) and exposure data. We calculated injury rates per 1000 athlete-exposures (AEs), injury rate ratios (IRRs) with 95% confidence intervals (CIs), and injury proportions by body site and diagnosis.

RESULTS

High school RIO documented 700 time-loss injuries during 481 687 AEs; the NCAA-ISP documented 1027 time-loss injuries during 287 856 AEs. The total injury rate during 2008-2009 through 2013-2014 was higher in college than in high school (2.55 versus 1.45/1000 AEs; IRR = 1.75; 95% CI = 1.54, 1.99). Most injuries occurred during competitions in high school (51.1%) and practices in college (63.8%). Rates were higher during competitions compared with practices in high school (IRR = 2.32; 95% CI = 2.00, 2.69) and college (IRR = 2.38; 95% CI = 2.09, 2.70). Concussion was the most common diagnosis among all high school and most collegiate player positions, and the main mechanism of contact was with a playing apparatus (eg, stick, ball). Ligament sprains were also common (HS RIO practices = 22.2%, competitions = 30.3%; NCAA-ISP practices = 25.5%, competitions = 30.9%).

CONCLUSIONS

Rates of injury were higher in college versus high school female lacrosse players and in competitions versus practices. Injury-prevention strategies are essential to decrease the incidence and severity of concussions and ligament sprains.

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Boys' Lacrosse (2008-2009 Through 2013-2014) and National Collegiate Athletic Association Men's Lacrosse (2004-2005 Through 2013-2014)

CONTEXT

The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of boys' and men's lacrosse injury data.

OBJECTIVE

To describe the epidemiology of injuries sustained in high school boys' lacrosse in the 2008-2009 through 2013-2014 academic years and collegiate men's lacrosse in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance.

DESIGN

Descriptive epidemiology study.

SETTING

Online injury surveillance from lacrosse teams of high school boys (annual average = 55) and collegiate men (annual average = 14).

PATIENTS OR OTHER PARTICIPANTS

Boys' and men's lacrosse players who participated in practices and competitions during the 2008-2009 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college.

MAIN OUTCOME MEASURE(S)

Athletic trainers collected time-loss (≥24 hours) injury and exposure data. Injury rates per 1000 athlete-exposures (AEs), injury rate ratios (IRRs) with 95% confidence intervals (CIs), and injury proportions by body site and diagnosis were calculated.

RESULTS

High School Reporting Information Online documented 1407 time-loss injuries during 662 960 AEs. The National Collegiate Athletic Association Injury Surveillance Program documented 1882 time-loss injuries during 390 029 AEs. The total injury rate from 2008-2009 through 2013-2014 was higher in college than in high school (3.77 versus 2.12/1000 AEs; IRR = 1.78; 95% CI = 1.63, 1.94). Most injuries occurred during competitions in high school (61.4%) and practices in college (61.4%). Injury rates were higher in competitions compared with practices in high school (IRR = 3.59; 95% CI = 3.23, 4.00) and college (IRR = 3.38; 95% CI = 3.08, 3.71). Lower limb injuries, muscle strains, and ligament sprains were common at both levels. Concussion was the most frequent competition diagnosis for all high school player positions.

CONCLUSIONS

Rates of time-loss injury were higher in college versus high school and in competitions versus practices. Attention to preventing common lower leg injuries and concussions, especially at the high school level, is essential to decrease their incidence and severity.

Multi-parametric analysis reveals metabolic and vascular effects driving differences in BOLD-based cerebrovascular reactivity associated with a history of sport concussion

Objective: Identify alterations in cerebrovascular reactivity (CVR) based on the history of sport-related concussion (SRC). Further explore possible mechanisms underlying differences in vascular physiology using hemodynamic parameters modeled using calibrated magnetic resonance imaging (MRI). Method: End-tidal targeting and dual-echo MRI were combined to probe hypercapnic and hyperoxic challenges in athletes with (n = 32) and without (n = 31) a history of SRC. Concurrent blood oxygenation level dependent (BOLD) and arterial spin labeling (ASL) data were used to compute BOLD-CVR, ASL-CVR, and other physiological parameters including resting oxygen extraction fraction (OEF0) and cerebral blood volume (CBV0). Multiple linear and logistic regressions were then used to identify dominant parameters driving group-differences in BOLD-CVR. Results: Robust evidence for elevated BOLD-CVR were found in athletes with SRC history spreading over parts of the cortical hemispheres. Follow-up analyses showed co-localized differences in ASL-CVR (representing modulation of cerebral blood flow) and hemodynamic factors representing static vascular (i.e., CBV0) and metabolic (i.e., OEF0) effects suggesting that group-based differences in BOLD-CVR may be driven by a mixed effect from factors with vascular and metabolic origins. Conclusion: These results emphasize that while BOLD-CVR offers promises as a surrogate non-specific biomarker for cerebrovascular health following SRC, multiple hemodynamic parameters can affect its relative measurements. Abbreviations: [dHb]: concentration of deoxyhemoglobin; AFNI: Analysis of Functional NeuroImages ( https://afni.nimh.nih.gov ); ASL: arterial spin labeling; BIG: position group: defensive and offensive linemen; BIG-SKILL: position group: full backs, linebackers, running backs, tight-ends; BOLD: blood oxygen level dependent; CBF: cerebral blood flow; CMRO2: cerebral metabolic rate of oxygen consumption; CTL: group of control subjects; CVR: cerebrovascular reactivity; fMRI: functional magnetic resonance imaging; FSL: FMRIB software library ( https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/ ); HC: hypercapnia; HO: hyperoxia; HX: group with history of concussion; M: maximal theoretical BOLD signal upon complete removal of venous dHb; pCASL: pseudo-continuous arterial spin labeling; PETCO2: end-tidal carbon dioxide; PETO2: end-tidal oxygen; SCAT: sport-concussion assessment tool; SKILL: position group: defensive backs, kickers, quarterbacks, safeties, wide-receivers; SRC: sport-related concussion.

Recommendations for the Emergency Department Prevention of Sport-Related Concussion

Sport-related concussion refers to the subset of concussive injuries occurring during sport activities. Similar to concussion from nonsport mechanisms, sport-related concussion is associated with significant morbidity, including migrainous headaches, disruption in normal daily activities, and long-term depression and cognitive deficits. Unlike nonsport concussions, sport-related concussion may be uniquely amenable to prevention efforts to mitigate these problems. The emergency department (ED) visit for sport-related concussion represents an opportunity to reduce morbidity by timely diagnosis and management using best practices, and through education and counseling to prevent a subsequent sport-related concussion. This article provides recommendations to reduce sport-related concussion disability through primary, secondary, and tertiary preventive strategies enacted during the ED visit. Although many recommendations have a solid evidence base, several research gaps remain. The overarching goal of improving sport-related concussion outcome through enactment of ED-based prevention strategies needs to be explicitly studied.

A New Game Plan for Concussion Education

Despite state laws requiring concussion education for youth sport stakeholders and a proliferation of educational programs, there has been little demonstrated impact on concussion reporting behaviors. We propose that this is because of four key limitations to existing approaches to concussion education: (1) deliberative decision making by the injured athlete is assumed, (2) interventions are often targeted at individuals rather than social systems, (3) education occurs once during preseason and is forgotten, and (4) dissemination challenges exacerbate health inequalities. Addressing these limitations, we propose a novel theoretic framework that situates individual behavior within a sport system's culture and their broader structural context. Concussion education programs should seek to facilitate safety-supportive interpersonal communication within and between stakeholder groups and influence attributes of groups that drive behavior, including shared values. Addressing the limitations outlined and drawing on the proposed conceptual framework, we describe a novel approach to concussion education: pregame safety huddles.

Preliminary Use of the Physical and Neurological Examination of Subtle Signs for Detecting Subtle Motor Signs in Adolescents With Sport-Related Concussion

Sensitive examination tools are needed to optimize evaluation after sports-related concussion. The Physical and Neurological Examination of Subtle Signs was preliminarily examined for sensitivity to motor changes in a pilot cohort of adolescents aged 13-17 yrs with sports-related concussion. A total of 15 adolescents (5 female adolescents) with sports-related concussion were evaluated up to three times: within 2 wks of injury, approximately 1 mo later (mean, 35 days between visits), and for those not recovered at the second visit, again after clinical recovery (mean, 70 days between the first and last visits for all participants). Comparison data were acquired from 20 age- and sex-matched healthy control athletes with no history of concussion who were evaluated twice (mean, 32 days apart). Main effects of group, time, and interaction effects were evaluated with an analysis of covariance, which controlled for socioeconomic status, times tested, and days between testing sessions. Adolescents with concussion had poorer Physical and Neurological Examination of Subtle Signs performance than controls did at all time points. Performance improved between visits within the concussion group, with no change within the control group. These findings suggest that the Physical and Neurological Examination of Subtle Signs merits additional study in larger cohorts and in combination with other markers of injury to facilitate an enhanced understanding of sports-related concussion and recovery.

Effects of repetitive subconcussive head trauma on the neuropsychological test performance of high school athletes: A comparison of high, moderate, and low contact sports

The aim of this study was to examine the neuropsychological test results of non-concussed high school athletes playing at three different levels of contact sports. Based on the concussion risk data of 12 different sports, a High Contact group (n=2819; wrestling/martial arts, cheerleading, track and field, football), a Moderate Contact group (n=2323; softball, basketball, soccer), and a Low Contact group (n=1580; baseball, volleyball, water polo, tennis, cross-country) were formed and compared in terms of their scores on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). The results revealed that the High Contact group obtained small but statistically poorer performances in ImPACT Visual Memory, Visual Motor Speed, Impulse Control, and Total Symptom scores compared to the Moderate and Low Contact groups. The High Contact group also had poorer Reaction Time scores compared to the Low Contact group. No differences between the Moderate and Low Contact groups were noted. The findings, along with prior similar results, tentatively raise concerns that participant in high contact sports, exposed to repetitive subconcussive head trauma, may be at greater risk for lowered neuropsychological functioning and increased symptoms, compared to other high school athletes. In view of the preliminary nature of this investigation, more research into the effects of frequent head impacts in high school sports is strongly recommended.

Patient, Injury, Assessment, and Treatment Characteristics and Return-to-Play Timelines After Sport-Related Concussion: An Investigation from the Athletic Training Practice-Based Research Network

OBJECTIVES

To describe the patient, injury, assessment and treatment characteristics, as well as return-to-play timelines and clinical findings at discharge for adolescent patients after sport-related concussion.

DESIGN

Retrospective analysis of electronic medical records.

SETTING

Athletic training facilities of secondary school members of the Athletic Training Practice-Based Research Network (AT-PBRN).

PATIENTS

In total, 1886 patient records were reviewed. [1204 (63.8%) male, 682 (36.2%) female, age = 15.3 ± 1.9 years, height = 169.5 ± 13.5 cm, mass = 70.3 ± 17.0 kg]. Patients were diagnosed with a concussion by an athletic trainer or team/directing physician.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Descriptive analysis of patient, injury, assessment, treatment, and participation status characteristics, as well as discharge information.

RESULTS

Injury demographic forms were completed for 1886 concussion cases. A concussion-specific evaluation form was completed for 55.9% (n = 1054) of cases. Treatment documentation was completed on 829 patients (44.0% of initial documented cases). Discharge forms were completed for 750 patients (40.0% of initial documented cases). Most cases were coded as 850.9-Concussion (85.5%, n = 642) and occurred during an in-season game (49.4%, n = 308). Time lost from competition was 24.9 ± 39.9 days.

CONCLUSIONS

Most concussion cases documented in this study were not on-field emergencies, as indicated by their normal clinical examinations and the lack of immediate referral to an emergency department. However, certain aspects of the clinical examination were often not assessed during the initial evaluation. These findings describe concussion assessment and recovery in adolescents and reinforce the need for a standardized approach to concussion assessment and appropriate documentation.

Concussion part II: Rehabilitation - The need for a multifaceted approach

INTRODUCTION

While most individuals recover in the initial days to weeks following a concussion, in up to 30% of cases symptoms and functional limitations may persist beyond the initial four weeks. There is emerging evidence that multifaceted physiotherapy techniques for individuals who have ongoing symptoms following concussion may be of benefit.

PURPOSE

The purpose of this masterclass article is to summarize the evidence for rehabilitation, describe treatment techniques and multifaceted interventions following concussion.

IMPLICATIONS

Concussion is a heterogenous injury and multiple types of rehabilitation may be required to address ongoing alterations in function. A greater understanding of evidence based rehabilitative techniques will enable the clinician to direct treatment and facilitate recovery for individuals who have ongoing symptoms following concussion.

Concussion - Part I: The need for a multifaceted assessment

INTRODUCTION

Concussion is among the most commonly occurring sport and recreation injuries in today's society. An understanding of the heterogenous nature of concussion will assist in directing a multifaceted and comprehensive interdisciplinary assessment following injury.

PURPOSE

The purpose of this masterclass article is to summarize the current state of the evidence in the area of concussion, describe typical symptom presentations and assessment techniques that may assist in directing appropriate management following concussion.

IMPLICATIONS

A comprehensive assessment including a thoughtful differential diagnosis will assist the clinician to direct care appropriately and efficiently in individuals who have suffered a concussion.

Incidence and Risk of Concussions in Youth Athletes: Comparisons of Age, Sex, Concussion History, Sport, and Football Position

Objective

This study was designed to determine concussion incidence, risk, and relative risk among middle and high school athletes participating in various sports.

Method

Data were retrospectively obtained from 10,334 athletes of 12 different sports in Hawaii. In addition to determining the overall concussion incidence, comparisons of incidence, risk, and relative risk were made according to age, sex, concussion history, sport, and football position.

Results

The overall incidence of concussion among youth athletes was 1,250 (12.1%). The relative risk for a concussion was almost two times greater in 18-year olds than in 13-year-old athletes. In comparable sports, girls had a 1.5 times higher concussion risk than boys. Athletes with a prior concussion had 3-5 times greater risk to sustain a concussion than those with no history of a concussion. Among varied sports, wrestling and martial arts had the highest relative risk of a concussion, followed by cheerleading, football, and track and field. No differences in concussion risks were found among the football players in different positions.

Conclusions

Older youths, females, those with a history of concussion, and those participating in high contact sports were found to have higher risks of sustaining a concussion. The findings increase awareness of concussion patterns in young athletes and raise concerns regarding protective strategies and concussion management in youth sports.

Lack of Sleep and Sports Injuries in Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

Although sleep has been identified as an important modifiable risk factor for injury, the effect of decreased sleep on sports injuries in adolescents is poorly studied. The objective of this study was to quantitatively and qualitatively review published literature to examine if a lack of sleep is associated with sports injuries in adolescents and to delineate the effects of chronic versus acute lack of sleep.

METHODS

PubMed (includes MEDLINE) and EMBASE databases were systematically searched using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they reported statistics regarding the relationship between sleep and sports injury in adolescents aged 19 years or younger published between January 1, 1997 and December 21, 2017. From these included studies, the following information was extracted: bibliographic and demographic information, reported outcomes related to injury and sleep, and definitions of injury and decreased sleep. A random effects model was then created to quantify the odds of injury with decreased sleep in adolescents.

RESULTS

Of 907 identified articles, 7 met inclusion criteria. Five studies reported that adolescents who chronically slept poorly were at a significantly increased likelihood of experiencing a sports or musculoskeletal injury. Two studies reported on acute sleep behaviors. One reported a significant positive association between acutely poor sleep and injury, whereas the other study reported no significant association. In our random effects model, adolescents who chronically slept poorly were more likely to be injured than those who slept well (OR, 1.58; 95% CI, 1.05-2.37; P=0.03).

CONCLUSIONS

Chronic lack of sleep in adolescents is associated with greater risk of sports and musculoskeletal injuries. Current evidence cannot yet definitively determine the effect of acute lack of sleep on injury rates.

LEVEL OF EVIDENCE

Level IV-systematic review of level II studies and one level IV study.

Musculoskeletal Injury Risk After Sport-Related Concussion: A Systematic Review and Meta-analysis

BACKGROUND

Clinical management of sport-related concussion typically involves a symptom checklist, clinical examination of mental status, and neurocognitive testing. However, recent studies have identified unresolved, impaired sensorimotor function after athletes return to sport. A review and meta-analysis of all current literature regarding risk of subsequent musculoskeletal (MSK) injury after concussion has yet to be published in the medical literature.

PURPOSE/HYPOTHESIS

To determine the odds that athletes will sustain MSK injury after concussion. It was hypothesized a priori that concussion would increase the risk for MSK injury.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

PubMed and Google Scholar were searched from January 2000 to November 2017. Reference lists of the included studies were manually searched. Two reviewers independently searched the literature for studies published in English that reported MSK injury after athletes returned to play following a concussion. Two independent reviewers completed data extraction using PRISMA guidelines and assessed study quality using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from the National Institutes of Health. Random effects meta-analyses were used to calculate odds ratio (OR) and incidence rate ratio (IRR) of MSK injury after concussion. The primary study outcome of interest was the number of athletes who sustained MSK injury after concussion.

RESULTS

Eight studies met inclusion criteria for meta-analysis. Meta-analysis results indicated that athletes who had a concussion had 2 times greater odds of sustaining a MSK injury than athletes without concussion (OR, 2.11; 95% CI, 1.46-3.06). In addition, athletes with concussion demonstrated a higher incidence of MSK injury after return to sport compared with nonconcussed athletes (IRR, 1.67; 95% CI, 1.42-1.96). Further analysis showed that both male and female athletes with concussion were at an increased risk of MSK injury compared with their respective same-sex, nonconcussed controls (OR > 1.56, P < .01).

CONCLUSION

Based on the evidence of higher risk of MSK injuries after concussion, standard clinical assessments for athletes with concussion should include not only physical symptoms and cognitive function before return to sport but also neuromuscular risk factors associated with increased risk for MSK injuries.