No abstract

Background Gait impairments have been well-studied in concussed athletes. However, the sex-specific effect of cumulative head impacts on gait is not well understood. When a cognitive task is added to a walking task, dual-task gait assessments can help amplify deficits in gait and are representative of tasks in everyday life. Dual-task cost is the difference in performance from walking (single-task) to walking with a cognitive load (dual-task). Purpose The objectives of this study were to explore the differences between sexes in 1) dual-task gait metrics, 2) gait metric changes from pre-season to post-concussion and post-season, and 3) the dual-task costs associated with gait metrics. Study Design Cross-sectional study Methods Over two seasons, 77 female athlete-seasons and 64 male athlete-seasons from collegiate club rugby teams participated in this study. Subjects wore inertial sensors and completed walking trials with and without a cognitive test at pre-season, post-season, and post-concussion (if applicable). Results Females athletes showed improvement in cadence (mean = 2.7 step/min increase), double support time (mean = -0.8% gait cycle time decrease), gait speed (mean = 0.1 m/s increase), and stride length (mean = 0.2 m increase) in both task conditions over the course of the season (p < 0.030). Male athletes showed no differences in gait metrics over the course of the season, except for faster gait speeds and longer stride lengths in the dual-task condition (p < 0.034). In all four gait characteristics, at baseline and post-season, females had higher dual-task costs (mean difference = 4.4, p < 0.003) than the males. Conclusions This results of this study showed little evidence suggesting a relationship between repetitive head impact exposure and gait deficits. However, there are sex-specific differences that should be considered during the diagnosis and management of sports-related concussion. Level of Evidence Level 2b

Objectives: Head impact exposure (HIE) in youth football is a public health concern. The objective of this study was to determine if one season of HIE in youth football was related to cognitive changes. Method: Over 200 participants (ages 9–13) wore instrumented helmets for practices and games to measure the amount of HIE sustained over one season. Pre- and post-season neuropsychological tests were completed. Test score changes were calculated adjusting for practice effects and regression to the mean and used as the dependent variables. Regression models were calculated with HIE variables predicting neuropsychological test score changes. Results: For the full sample, a small effect was found with season average rotational values predicting changes in list-learning such that HIE was related to negative score change: standardized beta (β) = -.147, t(205) = -2.12, and p = .035. When analyzed by age clusters (9–10, 11–13) and adding participant weight to models, the R2 values increased. Splitting groups by weight (median split), found heavier members of the 9–10 cohort with significantly greater change than lighter members. Additionaly, significantly more participants had clinically meaningful negative changes: X2 = 10.343, p = .001. Conclusion: These findings suggest that in the 9–10 age cluster, the average seasonal level of HIE had inverse, negative relationships with cognitive change over one season that was not found in the older group. The mediation effects of age and weight have not been explored previously and appear to contribute to the effects of HIE on cognition in youth football players.

Symptom inventories are generally only collected after a suspected concussion, but regular in-season monitoring may allude to clinical symptoms associated with repetitive subconcussive impacts and potential undiagnosed concussions. Despite sex-specific differences in symptom presentation and outcome of concussion, no return-to-play protocol takes sex into account. The objective of this study was to monitor a cohort of contact-sport athletes and compare the frequency and severity of in-season concussion-like symptom reporting between sexes. Graded symptom checklists from 144 female and 104 male athlete-seasons were administered weekly to quantify the effect of subconcussive impacts on frequency and severity of in-season symptom reporting. In-season, mean symptom severity score (SSS) ( p = 0.026, mean difference of 1.8), mean number of symptoms ( p = 0.044, mean difference of 0.9), max SSS ( p < 0.001, mean difference of 19.2), and max number of symptoms ( p < 0.001, mean difference of 6.8) were higher in the females. The females' survey results showed differences between elevated and concussed SSS ( p < 0.005, mean difference of 28.1) and number of symptoms reported ( p = 0.001, mean difference of 6.6). The males did not have a difference in SSS ( p = 0.97, mean difference of 1.12) nor in number of symptoms ( p = 0.35, mean difference of 1.96) from elevated to concussed athletes. Rugby players report concussion-like symptoms in the absence of a diagnosed concussion in-season. Female athletes reported elevated symptom frequencies with greater severities than the males, but both sexes reported considerable levels throughout the season.

ObjectiveThe objective of this study was to quantify elevated in-season presentation of concussion-like symptoms in the absence of diagnosed concussion in a cohort of collegiate rugby players.BackgroundIt is well known that many sports-related concussions are unreported. Athletes that do not immediately report concussion symptoms and continue to participate in activities are at higher risk for longer recoveries and sustain post-concussion symptoms longer. How regularly athletes experience elevated concussion symptoms in-season is unknown.Design/MethodsAthletes from men's and women's rugby teams were recruited and consented in accordance with the Virginia Tech Institutional Review Board. 63 males and 78 females participated over three seasons. Subjects completed a symptom and exposure query (SEQ) weekly throughout their season. The SEQ asked subjects if, in the past week, they experienced the 27 symptoms from the Graded Symptom Checklist for concussion. Subjects graded each symptom on a scale of 0–6, with 0 being no presentation and 6 being the most severe presentation. The graded severities of each symptom were summed to compute the overall Symptom Severity Score (SSS). Surveys that indicated confounding circumstances leading to symptoms were removed from analysis. The 99th percentile of SSS from baseline data was used as a metric of “elevated SSS,” which corresponded to an SSS of 11.Results1,214 SEQs were collected. There were 77 surveys from 43 athletes, 10 (15.8%) men and 33 (42.3%) women, who reported elevated SSS. In a given season, 16.3% of males and 41.7% of females reported elevated symptoms at least once. The surveys identified 11 additional suspected concussions based on symptom scores beyond the 8 that were clinically diagnosed.ConclusionsThis provides some evidence that constellations of concussion symptoms are commonly experienced by collegiate rugby athletes in-season. Some are at severities typically associated with concussion, but most are below current clinical concussion diagnostic thresholds.