Background:High school athletes are increasingly encouraged to participate in 1 sport year-round to increase their sport skills. However, no study has examined the association of competition volume, club sport participation, and sport specialization with sex and lower extremity injury (LEI) in a large sample of high school athletes.Hypothesis:Increased competition volume, participating on a club team outside of school sports, and high levels of specialization will all be associated with a history of LEI. Girls will be more likely to engage in higher competition volume, participate on a club team, and be classified as highly specialized.Study Design:Cross-sectional study.Level of Evidence:Level 3.Methods:High school athletes completed a questionnaire prior to the start of their competitive season regarding their sport participation and previous injury history. Multivariable logistic regression analyses were used to investigate associations of competition volume, club sport participation, and sport specialization with history of LEI, adjusting for sex.Results:A cohort of 1544 high school athletes (780 girls; grades 9-12) from 29 high schools completed the questionnaire. Girls were more likely to participate at high competition volume (23.2% vs 11.0%, χ2 = 84.7, P < 0.001), participate on a club team (61.2% vs 37.2%, χ2 = 88.3, P < 0.001), and be highly specialized (16.4% vs 10.4%, χ2 = 19.7, P < 0.001). Athletes with high competition volume, who participated in a club sport, or who were highly specialized had greater odds of reporting a previous LEI than those with low competition volume (odds ratio [OR], 2.08; 95% CI, 1.55-2.80; P < 0.001), no club sport participation (OR, 1.50; 95% CI, 1.20-1.88; P < 0.001), or low specialization (OR, 2.58; 95% CI, 1.88-3.54; P < 0.001), even after adjusting for sex.Conclusion:Participating in high sport volume, on a club team, or being highly specialized was associated with history of LEI. Girls were more likely to participate at high volumes, be active on club teams, or be highly specialized, potentially placing them at increased risk of injury.Clinical Relevance:Youth athletes, parents, and clinicians should be aware of the potential risks of intense, year-round participation in organized sports.

Sport-related concussion (SRC) is a major health problem, affecting millions of athletes each year. While the clinical effects of SRC (e.g., symptoms and functional impairments) typically resolve within several days, increasing evidence suggests persistent neurophysiological abnormalities beyond the point of clinical recovery after injury. This study aimed to evaluate cerebral blood flow (CBF) changes in acute SRC, as measured using advanced arterial spin labeling (ASL) magnetic resonance imaging (MRI). We compared CBF maps assessed in 18 concussed football players (age, 17.8 -1.5 years) obtained within 24 h and at 8 days after injury with a control group of 19 matched non-concussed football players. While the control group did not show any changes in CBF between the two time-points, concussed athletes demonstrated a significant decrease in CBF at 8 days relative to within 24 h. Scores on the clinical symptom (Sport Concussion Assessment Tool 3, SCAT3) and cognitive measures (Standardized Assessment of Concussion [SAC]) demonstrated significant impairment (vs. pre-season baseline levels) at 24 h (SCAT, p < 0.0001; SAC, p < 0.01) but returned to baseline levels at 8 days. Two additional computerized neurocognitive tests, the Automated Neuropsychological Assessment Metrics and Immediate Post-Concussion and Cognitive Testing, showed a similar pattern of changes. These data support the hypothesis that physiological changes persist beyond the point of clinical recovery after SRC. Our results also indicate that advanced ASL MRI methods might be useful for detecting and tracking the longitudinal course of underlying neurophysiological recovery from concussion.

Limited data exist comparing the performance of computerized neurocognitive tests (CNTs) for assessing sport-related concussion. We evaluated the reliability and validity of three CNTs—ANAM, Axon Sports/Cogstate Sport, and ImPACT—in a common sample. High school and collegiate athletes completed two CNTs each at baseline. Concussed (n = 165) and matched non-injured control (n = 166) subjects repeated testing within 24 hr and at 8, 15, and 45 days post-injury. Roughly a quarter of each CNT's indices had stability coefficients (M = 198 day interval) over .70. Group differences in performance were mostly moderate to large at 24 hr and small by day 8. The sensitivity of reliable change indices (RCIs) was best at 24 hr (67.8%, 60.3%, and 47.6% with one or more significant RCIs for ImPACT, Axon, and ANAM, respectively) but diminished to near the false positive rates thereafter. Across time, the CNTs' sensitivities were highest in those athletes who became asymptomatic within 1 day before neurocognitive testing but was similar to the tests' false positive rates when including athletes who became asymptomatic several days earlier. Test–retest reliability was similar among these three CNTs and below optimal standards for clinical use on many subtests. Analyses of group effect sizes, discrimination, and sensitivity and specificity suggested that the CNTs may add incrementally (beyond symptom scores) to the identification of clinical impairment within 24 hr of injury or within a short time period after symptom resolution but do not add significant value over symptom assessment later. The rapid clinical recovery course from concussion and modest stability probably jointly contribute to limited signal detection capabilities of neurocognitive tests outside a brief post-injury window.

Context In many US high schools, the athletic trainer (AT) has the responsibility to identify and manage athletes with concussions. Although the availability of ATs varies a great deal among schools, how the level of AT availability in high schools affects the reported incidence and management of sport-related concussions (SRCs) is unknown. Objective To determine how the presence of an AT affects the reporting and management of SRCs. Design Prospective cohort study. Patients or Other Participants A total of 2459 (female = 37.5%, age = 16.1 ± 1.2 years) athletes from 31 Wisconsin high schools were categorized as having low availability (LoAT), mid availability (MidAT), or high availability (HiAT) of ATs. Athletic trainers recorded the incidence, days lost from sport, and postconcussion management through return to sport. The incidence of SRC reporting among categories was examined using a multivariate Cox proportional hazards model. Fisher exact tests were used to determine if postconcussion management differed based on AT availability. Results The incidence of reported SRCs was lower for the LoAT schools (2.4%) compared with the MidAT (5.6%, hazard ratio = 2.59, P = .043) and HiAT (7.0%, hazard ratio = 3.33, P = .002) schools. The median time before the first AT interaction was longer for LoAT schools (24.0 hours) than for MidAT (0.5 hours, post hoc P = .012) and HiAT (0.2 hours, post hoc P = .023) schools. The number of post-SRC interactions was different in all groups (LoAT = 2 interactions, MidAT = 3, and HiAT = 4; all post hoc P values &lt; .05). Days lost were greater for MidAT and HiAT (both 14 days lost) schools compared with LoAT schools (11.5 days lost, post hoc P = .231 and P = .029, respectively). Athletes at LoAT schools were less likely to undergo a return-to-play protocol (9/18 SRCs, 50.0%) than athletes at MidAT (44/47 SRCs, 93.6%; post hoc P = .001) or HiAT (64/64 SRCs, 100%; post hoc P &lt; .001) schools. Conclusions The level of AT availability positively influenced the reported incidence of SRCs as well as postconcussion management activities in this sample of high schools.

BackgroundThere have been no large randomised controlled trials to determine whether soccer headgear reduces the incidence or severity of sport-related concussion (SRC) in US high school athletes.ObjectiveWe aimed to determine whether headgear reduces the incidence or severity (days out from soccer) of SRCs in soccer players.Methods2766 participants (67% female, age 15.6±1.2) (who undertook 3050 participant years) participated in this cluster randomised trial. Athletes in the headgear (HG) group wore headgear during the season, while those in the no headgear (NoHG) group did not. Staff recorded SRC and non-SRC injuries and soccer exposures. Multivariate Cox proportional hazards models were used to examine time-to-SRC between groups, while severity was compared with a Wilcoxon rank-sum test.Results130 participants (5.3% female, 2.2% male) sustained an SRC. The incidence of SRC was not different between the HG and NoHG groups for males (HR: 2.00 (0.63–6.43) p=0.242) and females (HR: 0.86 (0.54–1.36) p=0.520). Days lost from SRC were not different (p=0.583) between the HG group (13.5 (11.0–018.8) days) and the NoHG group (13.0 (9.0–18.8) days).ConclusionsSoccer headgear did not reduce the incidence or severity of SRC in high school soccer players.Trial registration numberNCT02850926.