LIMBIC military and tactical athlete research study: making lemonade 101.

The Long-term Impact of Military-relevant Brain Injury Consortium-Military and Tactical Athlete Research Study (LIMBIC MATARS) program established in 2020 is comprised of 22 universities and health systems across the United States. The LIMBIC MATARS Consortium's goal is to increase understanding of the complexities of concussion in collegiate athletes by leveraging extant retrospective and novel prospective data sets through the application of innovative research designs. The manuscripts in this special issue represent findings from clinical data sets based on consensus-derived common data elements collected from the 2015-2016 to 2019-2020 sport seasons that include 1311 cases of collegiate athletes diagnosed with concussion. Using these data, LIMBIC MATARS investigators addressed hypotheses that included (1) factors, including access to athletic trainers, biological sex, and ADHD, that may influence recovery from concussion, (2) predisposing risks associated with reinjury after return-to-sport, such as sport type, and (3) therapeutic targets for intervention including language barriers, physical activity, return-to-learn, and sleep. This commentary introduces the methodology and 10 descriptive studies highlighting initial findings from the Consortium.

Academic adjustments and concussion recoveries in NCAA student-athletes: a LIMBIC MATARS investigation.

OBJECTIVE: The aim of this study was to investigate the association between academic adjustments and recovery from sport-related concussions (SRCs) in collegiate athletes. MATERIALS AND METHODS: A retrospective medical chart review was performed between the 2015-2016 and 2019-2020 sport seasons at 11 Long-term Impact of Military-relevant Brain Injury Consortium Military and Tactical Athlete Research Study (LIMBIC MATARS) sites. Days between injury and symptom resolution, and injury and return to sport (dependent variables) for collegiate athletes who did or did not receive academic adjustments (independent variable) were analyzed using Mann-Whitney U tests. RESULTS: The number of days between date of injury and symptom-resolution between those who did (median = 9 [interquartile range = 5,16]) and did not have (7[3,12]) academic adjustments were statistically different (z=-2.76, p < 0.01, r=-0.17). However, no differences were observed between days to return to sport among those who did (14[10,22]) and did not (13[8,20]) receive assigned academic adjustments (z= -1.66, p = 0.10, r= -.10). CONCLUSIONS: Recovery trajectories were similar between athletes diagnosed with a SRC who did or did not receive academic adjustments.. Our findings suggest academic adjustments supported recovery for those who needed academic adjustments. Clinicians and healthcare professionals should assist and support collegiate athletes after SRCs on an individual basis, including academic adjustments when appropriate based on patient presentation.

Exploring the relationship between contraceptive medication use and concussion recovery in female collegiate athletes: a LIMBIC MATARS consortium investigation.

OBJECTIVE: While recovery from concussion is variable, women are more likely to report symptoms, experience worse outcomes, and have longer recovery trajectories following concussion than men. Preliminary data suggest that hormonal fluctuations, specifically progesterone, may be associated with this variability. This study aimed to understand the effect of contraceptive medication on concussion recovery. METHODS: A retrospective chart review using consensus-based common data elements was conducted at 11 NCAA institutions as part of the LIMBIC MATARS consortium. Participants included female collegiate athletes diagnosed with a concussion who did (n = 117) or did not report (n = 339) contraceptive medication use. Number of days between diagnosis and symptom resolution were compared using Mann-Whitney U tests. Self-reported diagnosis of attention deficit hyperactivity disorder, concussion history, anxiety, and depression was compared using Chi-squared tests. RESULTS: The proportions of participants who did or did not take contraceptive medication were similar across covariates. Female athletes regardless of contraceptive medication use recovered similarly following a concussion. CONCLUSIONS: Our findings suggest that contraceptive medication use did not significantly impact concussion recovery. Future prospective investigations should examine documentation practices and operationalize terminology for hormonal contraceptive medication to better understand their role on recovery from sport-related concussion in female collegiate athletes.

Influence of sleep symptoms on recovery from concussion in collegiate athletes: a LIMBIC MATARS consortium investigation.

OBJECTIVE: Changes in sleep quality and quantity are commonly endorsed by individuals following a concussion. Limited data exists examining the role of sleep disturbances within 72 hours, and throughout recovery, from concussion. The objective of this study was to determine if the number of days to symptom resolution varied between collegiate athletes with or without sleep-related symptoms following a concussion. DESIGN: Retrospective chart review. METHODS: Collegiate athletes (n = 539) who were diagnosed with a concussion between the 2015-2020 sport seasons participated in this retrospective chart review. Participants were divided into groups based on the presence or absence of sleep symptoms within 72 hours of a diagnosed concussion. A Mann-Whitney U test was used to compare days to symptom resolution between groups with α = 0.05. RESULTS: Of the 539 participants, 250 (46.3%) reported sleep-related symptoms. Participants with sleep-related symptoms took significantly longer (U = 30656, p = 0.002) to report symptom resolution at rest (median [full range] = 8.00[0-423]) as compared to participants who did not report sleep-related symptoms (6.00[0-243] days). CONCLUSION: Collegiate athletes that report sleep-related symptoms immediately following concussion (<72 hours) were observed to take, on median, two days longer to achieve symptom resolution at rest when compared to athletes who did not endorse the same symptoms.

Access to athletic trainers and sex as modifiers of time to reach clinical milestones after sport-related concussion in collegiate athletes.

OBJECTIVE: Investigate whether an athlete's biological sex and exposure to a dedicated athletic trainer (AT) were related to clinical milestones after a sports-related concussion (SRC). DESIGN: Retrospective chart review. METHODS: Medical charts of collegiate athletes (n = 196 [70.9% female]) diagnosed with SRC were reviewed to extract: biological sex, dedicated AT exposure for their sport (yes/no), and time (days) to reaching clinical milestones (diagnosis, symptom resolution, unrestricted return to sport [RTS]). Mann-Whitney U tests were used to determine whether time to clinical milestones differed by sex, AT exposure, or their interaction. Proportions of same-day diagnoses and times to diagnosis, symptom resolution, and unrestricted RTS were evaluated with chi-squared and spearman's rank correlations, respectively. RESULTS: There were no significant differences in times to reaching any clinical milestone by sex, AT exposure, or their interaction (ps > 0.05). Forty-three percent of participants were diagnosed on the day of their SRC. This did not differ by sex or AT exposure (ps > 0.29). Longer times to SRC diagnosis were associated with more days to symptom resolution (ρ = 0.236, p = 0.001) and unrestricted RTS (ρ = 0.223, p < 0.001). CONCLUSIONS: Athlete sex and AT exposure were not associated with times to reach any clinical milestone; however, delayed diagnosis was associated with longer times to reach clinical recovery.

Concussion diagnosis and recovery in relation to collegiate athletic department classification: a LIMBIC MATARS consortium investigation.

PURPOSE: We investigated time to reach concussion diagnosis and recovery milestones in collegiate athletes relative to their schools' National Collegiate Athletic Association (NCAA) classification. METHODS: We retrospectively examined 849 (43.1% female) concussion cases from 11 NCAA institutions (Division I Power 5 [n = 4], Division I Non-Power 5 [n = 4], and Division II/III [n = 3]) from the 2015-16 to 2019-20 athletic seasons. Our primary outcome measures were days to reach specific clinical milestones following concussion. RESULTS: Median (IQR) time from injury to diagnosis was significantly longer at Division II/III institutions (1 [0-4] days) compared to Division I Power 5 (0 [0-1] days) and Division I Non-Power 5 (0 [0-1] days) institutions (p < 0.001). Likewise, Division II/III athletes (15 [11-22] days) took significantly longer to return to sport after concussion than Division I Power 5 (10 [7-16] days) and Division I Non-Power 5 (11 [7-18.5] days) athletes (p < 0.001). CONCLUSION: Division II/III athletes had delayed concussion diagnoses and return to sport timelines compared to Division I athletes. Our results suggest that differences in sports medicine resources across NCAA divisions may influence injury recognition and recovery in collegiate athletes with concussion.

Physical activity and recovery following concussion in collegiate athletes: a LIMBIC MATARS Consortium Investigation.

OBJECTIVE: To investigate whether routine daily activities (RDA), non-prescribed exercise (Non-ERx), or prescribed exercise (ERx) were associated with recovery from sport-related concussion (SRC) in collegiate athletes. MATERIALS AND METHODS: Data for this cross-sectional, retrospective chart review of collegiate athletes diagnosed with SRC (n = 285[39.6% female], age = 19.5 ± 1.4 years) were collected during the 2015-16 to 2019-20 athletic seasons. The independent variable was group (RDA, Non-ERx, ERx). Dependent variables included days from date of diagnosis to symptom resolution (Dx-SR) and SR to return to sport (SR-RTS). RESULTS: Those in the Non-ERx group took nearly 1.3 times longer to achieve SR (IRR = 1.28, 95% CI: 1.11, 1.46) and, 1.8 times longer for RTS (IRR = 1.82, 95% CI: 1.11, 2.71) when compared to those in the RDA group. No other comparisons were significant. CONCLUSION: Collegiate athletes in the Non-ERx group took approximately 1 week longer to achieve SR as compared to the RDA and ERx groups. Our findings suggest that if exercise is recommended following SRC, it must be clearly and specifically prescribed. If exercise parameters cannot be prescribed, or monitored, RDA appear to be similarly beneficial during recovery for collegiate athletes with concussion.

Sport Type and Risk of Subsequent Injury in Collegiate Athletes Following Concussion: a LIMBIC MATARS Consortium Investigation.

OBJECTIVE: To investigate the association between sport type (collision, contact, non-contact) and subsequent injury risk following concussion in collegiate athletes. MATERIALS AND METHODS: This retrospective chart review of 248 collegiate athletes with diagnosed concussions (age: 20.0 ± 1.4 years; height: 179.6 ± 10.9 cm; mass: 79.0 ± 13.6 kg, 63% male) from NCAA athletic programs (n = 11) occurred between the 2015-2020 athletic seasons. Acute injuries that occurred within six months following concussion were evaluated. Subsequent injuries were grouped by lower extremity, upper extremity, trunk, or concussion. The independent variable was sport type: collision, contact, non-contact. A Cox proportional hazard model was used to assess the risk of subsequent injury between sport types. RESULTS: Approximately 28% (70/248) of athletes sustained a subsequent acute injury within six months post-concussion. Collision sport athletes had a significantly higher risk of sustaining any injury (HR: 0.41, p < 0.001, 95% CI: 0.28, 0.62), lower extremity (HR: 0.55, p = 0.04, 95% CI: 0.32, 0.97), and upper extremity (HR: 0.41, p = 0.01, 95% CI: 0.20, 0.81) injuries following concussion. No differences between sport types were observed for other injuries. CONCLUSION: Collision sport athletes had a higher rate of any subsequent injury, lower, and upper extremity injuries following concussion. Future research should focus on sport-specific secondary injury prevention efforts.

Recovery Is Similar Between Black and White College Athletes Following Sport-Related Concussion.

CONTEXT: Racial identity may associate with clinical outcomes following sport-related concussion (SRC). This study compared clinical outcome scores before and after recovery from a SRC between Black or White college athletes. DESIGN: Prospective cohort. METHODS: Participants were self-reported White (n = 61, 18.5 [1.1] y of age) and Black (n = 24, 18.3 [1.1] y of age) NCAA Division 1 college athletes. The revised Head Injury Scale (HIS-r), the Immediate Postconcussion and Cognitive Test (ImPACT) battery, and the Sensory Organization Test (SOT) at baseline (T1), upon symptom resolution (T2) following a diagnosed SRC, and upon establishing a new baseline assessment (T3). Race was collected from paper and electronic medical records. The revised Head Injury Scale total symptom severity, ImPACT's Verbal Memory, Visual Memory, Visual Motor Speed (VMS), and Reaction Time, and the SOT Equilibrium Score, were compared between groups at each time point. Multivariate analyses of variance (2 [group] × 3 [time]) were used to compare revised Head Injury Scale, ImPACT, and SOT outcome scores. Post hoc analyses consisted of independent and paired sample t tests. RESULTS: A significant main effect for time (λ = 0.66, F2,82 = 21.55, P < .001, ηp2=.34) was observed for the SOT. White athletes significantly improved on the Equilibrium Score between all time points (all P < .006). Similarly, Black athletes significantly improved on the Equilibrium Score between T1-T2 and T1-T3 (all P < .001). A significant main effect of time was observed for ImPACT's Verbal Memory, Visual Memory, and VMS outcome scores (all P < .001). VMS improved for White athletes between T1-T2 (P = .02) and T3 (P = .006). Black athletes had improved VMS scores between T1-T3 (P = .015) and T2-T3 (P = .005). A between-group difference was observed for VMS at T2 (P = .004). CONCLUSIONS: There was 1 small and not clinically significant difference between groups for the VMS score at T2. Overall, groups performed consistently or improved upon their baseline balance, cognition, and symptom outcome scores at clinically relevant time points following a SRC.

The Influence of Race on Time to Symptom Resolution Following Sport Concussion in Collegiate Athletes.

CONTEXT: Race has been shown to influence computerized neurocognitive test scores, motor function test scores, and reported symptomology following sport-related concussion (SRC). However, the effect race may have on recovery time following SRC remains unknown. The objective of this study was to determine the influence of race on days until symptom free from SRC in NCAA Division 1 collegiate athletes. DESIGN: Prospective cohort study. METHODS: Participants were Black (n = 53 [28% female]) and White (n = 150 [43.3% female]) who were on average 19.0 (1.21) and 20.2 (1.3) years of age, respectively. Data were collected from the 2015-2016 to 2020-2021 collegiate sport seasons. Participants were evaluated before and after an SRC at empirically derived time points. The primary outcome measure was time until symptom free (days). Additional outcomes included baseline and postinjury Immediate Postconcussion Assessment and Cognitive Test and Sensory Organization Test (SOT) scores. A Mann-Whitney U test compared days to symptom free between groups. Immediate Postconcussion Assessment and Cognitive Test and SOT outcome scores were analyzed using a 2 (group) × 2 (time) analysis of variance. RESULTS: White participants had a longer median recovery time (9 d) to symptom free compared with Black participants (6 d [P = .04]). Statistically significant differences were observed between Black 87.3 (9.84) and White 90.4 (8.30) groups for Immediate Postconcussion Assessment and Cognitive Test's verbal memory composite score (P = .03). Postinjury, White participants scored significantly higher 44.5 (5.63) on visual motor speed compared with Black participants (42.4 (5.90) [P = .02]). Within-group SOT differences between baseline and postinjury testing were observed in both groups (all P < .001). CONCLUSIONS: Black collegiate athletes achieved symptom resolution sooner than White athletes. We did not explore underlying sociocultural factors such as socioeconomic status or previous concussion education, which may have influenced our results. Future studies should explore factors that may contextualize these findings.

An Absence of Persistent Postural Stability Deficits Following a Sport Concussion in Collegiate Athletes.

OBJECTIVE: The purpose of our study was to determine whether persistent postural stability deficits exist in athletes following sport concussion (SC) in comparison with preinjury (baseline) values using Sample Entropy (SampEn). SETTING: Sports medicine clinic. PATIENTS OR OTHER PARTICIPANTS: Participants consisted of 71 collegiate athletes (44 male, 27 female) with an average age of 19.9 ± 0.96 years who had a history of 1 concussion that occurred during their time as a collegiate athlete. DESIGN: In our prospective, cohort design participants completed the Sensory Organization Test (SOT) at baseline, upon reporting symptom-free following a diagnosed SC, and upon establishing a new baseline prior to the start of the subsequent sport season. MAIN OUTCOME MEASURES: The SOT's condition scores were calculated and analyzed in alignment with the manufacturer's instructions. SampEn was calculated in the anterior-posterior (AP) and medial-lateral (ML) directions from the center-of-pressure oscillations over the 20-second time series for each SOT condition. The SOT and SampEn outcome scores for each condition were analyzed with repeated-measures analyses of variance. RESULTS: Significant main effects were observed for the SOT's conditions 3 ( F1.6, 114.8 = 7.83, P = .001, η2 = 0.10 [0.02-0.20]), 5 ( F1.8, 126.8 = 11.53, P < .001, η2 = 0.14 [0.04-0.25]), and 6 ( F1.9, 134.5 = 25.11, P < .001, η2 = 0.26 [0.14-0.37]), with significant improvements across time. Significant main effects were also observed for SampEn in the AP direction for conditions 3 ( F2, 140 = 7.59, P = .001, η2 = 0.10 [0.02-0.19]) and 6 ( F2, 140 = 6.22, P = .003, η2 = 0.08 [0.011-0.170]), with significant improvements across time. CONCLUSIONS: Following a diagnosed SC, our results suggest that collegiate athletes returned if not exceeded baseline values at the symptom-free and new baseline assessments. The application of linear and nonlinear measures of postural stability following a SC yielded similar outcomes in conjunction with a baseline assessment. Our findings support the clinical utility of the baseline SC assessment when evaluating persisting balance deficits when using linear or nonlinear measures.

Kinesiophobia Is Related to Acute Musculoskeletal Injury Incidence Following Concussion.

CONTEXT: Athletes with a history of sport concussion (SC) have an increased risk of musculoskeletal injury (MSK); however, the underlying mechanisms have yet to be determined. The purpose of our study was to evaluate kinesiophobia in college athletes with or without a time-loss MSK within 180 days of unrestricted return to play following a SC. DESIGN: This was a retrospective cohort study within a sports medicine facility. METHODS: Participants were eligible if they were diagnosed with a SC, completed the Tampa Scale of Kinesiophobia (TSK), and completed an unrestricted return to play. Fifty-six college athletes (40 men and 16 women) with an average age of 19.5 (1.25) years, height of 183.5 (10.45) cm, and mass of 94.72 (24.65) kg, were included in the study. MSK participants were matched to non-MSK participants 1:1. Demographic and TSK outcome scores were compared using independent t tests. The proportion of participants in each group who scored above the clinical threshold (TSK ≥ 37) was compared using a chi-square analysis. Alpha was set at α = .05. RESULTS: The MSK group (31.2 [6.30]) reported similar TSK scores to the matched group (28.9 [3.34]; t54 = 1.70, P = .10, d = 0.45 [-0.08 to 0.97]). A greater proportion of athletes who were diagnosed with an MSK-reported scores above the cutoff (χ2[1] = 6.49, P = .01). CONCLUSIONS: Athletes diagnosed with SC had similar kinesiophobia values regardless of MSK status. However, a higher proportion of athletes with a time-loss MSK injury reported a TSK score greater than the clinical cutoff. Our results suggest that factors such as kinesiophobia should be considered following a SC.

Psychometric Properties of Computerized Cognitive Tools and Standard Neuropsychological Tests Used to Assess Sport Concussion: A Systematic Review.

Athletic programs are more frequently turning to computerized cognitive tools in order to increase efficiencies in concussion assessment. However, assessment using a traditional neuropsychological test battery may provide a more comprehensive and individualized evaluation. Our goal was to inform sport clinicians of the best practices for concussion assessment through a systematic literature review describing the psychometric properties of standard neuropsychological tests and computerized tools. We conducted our search in relevant databases including Ovid Medline, Web of Science, PsycINFO, and Scopus. Journal articles were included if they evaluated psychometric properties (e.g., reliability, sensitivity) of a cognitive assessment within pure athlete samples (up to 30 days post-injury). Searches yielded 4,758 unique results. Ultimately, 103 articles met inclusion criteria, all of which focused on adolescent or young adult participants. Test-retest reliability estimates ranged from .14 to .93 for computerized tools and .02 to .95 for standard neuropsychological tests, with strongest correlations on processing speed tasks for both modalities, although processing speed tasks were most susceptible to practice effects. Reliability was improved with a 2-factor model (processing speed and memory) and by aggregating multiple baseline exams, yet remained below acceptable limits for some studies. Sensitivity to decreased cognitive performance within 72 h of injury ranged from 45%-93% for computerized tools and 18%-80% for standard neuropsychological test batteries. The method for classifying cognitive decline (normative comparison, reliable change indices, regression-based methods) affected sensitivity estimates. Combining computerized tools and standard neuropsychological tests with the strongest psychometric performance provides the greatest value in clinical assessment. To this end, future studies should evaluate the efficacy of hybrid test batteries comprised of top-performing measures from both modalities.

Mood, Psychological, and Behavioral Factors of Health-Related Quality of Life Throughout Recovery From Sport Concussion.

OBJECTIVE: To measure alterations in mood, psychological, and behavioral factors in collegiate athletes throughout recovery from sport concussion (SC) compared with matched controls. SETTING: University research laboratory. PARTICIPANTS: Twenty (55% female) division I collegiate athletes with SC (19.3 ± 1.08 years old, 1.77 ± 0.11 m, 79.6 ± 23.37 kg) and 20 (55% female) uninjured matched controls (20.8 ± 2.17 years old, 1.77 ± 0.10 m, 81.9 ± 23.45 kg). DESIGN: Longitudinal case control. MAIN MEASURES: Self-reported concussion-related symptoms, anxiety, resilience, stigma, sleep disturbance, fatigue, and appetite were assessed at 3 time points in the SC group: T1 (≤72 hours of SC), T2 (7 days after T1), and TF (after symptom resolution). Control participants were evaluated at similar intervals. Group and group-by-sex differences were assessed using repeated-measures analyses of variance. Post hoc analyses were performed with Tukey's honestly significant difference (HSD) and paired-sample t tests. RESULTS: The SC group had greater sleep disturbance than controls at T1 (P = .001; d = 1.21) and endorsed greater stigma at all time points (P ≤ .03; d ≥ 0.80). Stigma (F(2) = 3.68; P = 0.03; η2p = 0.12), sleep disturbance (F(2) = 5.27; P = .008; η2p = 0.15), and fatigue (F(2) = 3.46; P = .04; η2p = 0.11) improved throughout recovery in those with SC only. No differences were observed between males and females (P > .05). CONCLUSION: Sleep disturbance and stigma were negatively affected by SC, highlighting potential areas for clinical interventions to maximize recovery in males and females.

Reevaluating clinical assessment outcomes after unrestricted return to play following sport-related concussion.

PRIMARY OBJECTIVE: The objective of this study was to examine neurocognition, postural control, and symptomology at multiple timepoints following concussion. We hypothesized that collegiate athletes would perform similar to or better than their baseline in terms of each outcome at both timepoints. RESEARCH DESIGN: This was a retrospective study of 71 collegiate athletes (18.3 ± 0.89 years old; 182.2 ± 10.05 cm; 84.2 ± 20.07 kg) to observe changes in outcomes from a previously established clinical protocol. METHODS AND PROCEDURES: Participants were administered ImPACT™, the Sensory Organization Test (SOT), and the revised head injury scale (HIS-r) prior to their seasons (baseline); upon reporting symptom-free following concussion (post-injury); and approximately 8-months after return-to-play to establish a new baseline. MAIN OUTCOMES AND RESULTS: There were no changes in ImPACT scores or HIS-r reporting over time. ImPACT total symptom score (TSS) decreased over time (p = .002, ηp2 = 0.08). Significant main effects occurred for the SOT equilibrium score (p < .01, ηp2 = 0.34) and Vestibular sensory ratio (p < .001, ηp2 = 0.22). CONCLUSIONS: Our data suggest no decline in neurocognition, balance, or symptom burden approximately eight months post-injury. As clinicians continue to explore "best practices" for concussion management and potential long-term implications of these injuries it is important to monitor outcome measures longitudinally.

Detection of Gluteal Changes Using Ultrasound Imaging During Phases of Gait in Individuals With Medial Knee Displacement.

Context: Medial knee displacement (MKD) is a common risk factor for lower-extremity injury and is related to altered gluteal muscle activity. Ultrasound imaging (USI) is a reliable means to explore mechanical muscle activity; however, no information exists regarding USI of the gluteals during gait in an MKD population. Objective: To determine differences in USI gluteal muscle activity during gait in individuals with and without MKD. Design: Descriptive laboratory study. Setting: University research laboratory. Participants: Out of 28 participants, 14 exhibiting MKD unilaterally during a single-leg squat (19.36 [1.51] y, 169.73 [7.50] cm, and 62.01 [10.57] kg; 10 females) and 14 matched non-MKD subjects (20.29 [1.73] y, 167.24 [9.07] cm, and 67.53 [16.03] kg). Interventions: Bilateral B-mode USI of the gluteus maximus (Gmax) and gluteus medius (Gmed) muscles during quiet stance, heel strike, and a 10-second treadmill walking clip. Main Outcome Measures: Gluteal thickness measures normalized to quiet stance yielded activity ratios, and percentage of muscle thickness change was assessed between heel strike and quiet stance. Differences between groups were assessed with Cohen's d effect sizes with 95% confidence intervals. Activity ratios with 90% confidence intervals plotted on 10% intervals from 0% to 100% of gait were used to compare groups and limbs. A subsample of images was measured to determine intertester reliability. Results: USI revealed decreased Gmax and Gmed percent change at heel strike (%change = -9.57% [7.15%] and -8.76% [4.26%], respectively). The MKD limb compared with the contralateral limb exhibited decreased Gmed activity ratio at 30% of gait (MKD = 0.89 [0.056]; non-MKD = 1.01 [.052]). Intertester reliability was excellent for gluteus maximus (intraclass correlation coefficient = .987 [.014]) and Gmed (intraclass correlation coefficient = .989 [.013]) measurements. Conclusions: USI highlighted gluteal activity differences of MKD limbs during gait, which may contribute to inadequate hip stabilization during this daily repetitive task. These findings potentiate the use of USI as an intervention- or screening-based visual tool.

Concussion and the Sleeping Brain.

BACKGROUND: Emerging research has suggested sleep to be a modifier of the trajectory of concussion recovery in adolescent and adult populations. Despite the growing recognition of the relationship between sleep and concussion, the mechanisms and physiological processes governing this association have yet to be established. MAIN BODY: Following a concussion, a pathophysiologic cascade of events occurs, characterized by numerous factors including microglia activation, ionic imbalance, and release of excitatory neurotransmitters. Importantly, each of these factors plays a role in the regulation of the sleep-wake cycle. Therefore, dysregulation of sleep following injury may be a function of the diffuse disruption of cerebral functioning in the wake of both axonal damage and secondary physiological events. As the onset of sleep-related symptoms is highly variable following a concussion, clinicians should be aware of when and how these symptoms present. Post-injury changes in sleep have been reported in the acute, sub-acute, and chronic phases of recovery and can prolong symptom resolution, affect neurocognitive performance, and influence mood state. Though these changes support sleep as a modifier of recovery, limited guidance exists for clinicians or their patients in the management of sleep after concussion. This may be attributed to the fact that research has correlated sleep with concussion recovery but has failed to explain why the correlation exists. Sleep is a complex, multifactorial process and the changes seen in sleep that are seen following concussion are the result of interactions amongst numerous processes that regulate the sleep-wake cycle. SHORT CONCLUSION: The assessment and management of sleep by identifying and considering the biological, sociological, and psychological interactions of this multifactorial process will allow for clinicians to address the dynamic nature of changes in sleep following concussion.

The Effect of Exercise on a Novel Dual-Task Assessment for Sport Concussion.

PURPOSE: This study aimed to determine the effect of exercise on cognitive and motor performance and the subsequent test-retest reliability of a novel dual-task (DT) assessment in nonconcussed college students. METHODS: Sixty nonconcussed college students (53.3% female) with an average age (±SD) of 20.5 ± 1.34 yr, height of 171.7 ± 9.33 cm, and mass of 69.3 ± 12.23 kg were included in the study. Participants were assigned to an exercise ( n = 30) or rest ( n = 30) intervention group and completed two study visits that were separated by a 2-wk test-retest interval. At each visit, participants completed a novel DT assessment that consisted of the concurrent administration of the Standardized Assessment of Concussion (SAC) and tandem gait (TG) before the exercise or rest intervention. After the DT assessment at the first visit, participants in the exercise group performed moderate-intensity exercise, whereas the rest group sat quietly for 30 min. After the intervention, both groups were readministered the DT assessment. At the second visit, the same procedures were followed, except that each group was administered the opposite intervention (e.g., the exercise group completed the rest intervention). A composite TG (cTG) score was calculated by summing the average time to complete the TG pattern during each SAC domain (immediate memory, digits backwards, months in reverse order, delayed recall). An ANCOVA was conducted to assess postintervention differences while controlling for preintervention performance. Test-retest reliability was assessed using intraclass correlation coefficients (ICC 3,2 ) with 95% confidence intervals, with all analyses performed with α = 0.05. RESULTS: SAC and cTG performance was similar ( P values > 0.05) from preintervention to postintervention for the rest or exercise protocols. Good (rest: ICC = 0.77 (0.62-0.87); exercise: ICC = 0.84 (0.73-0.90)) and excellent (rest: ICC = 0.97 (0.94-0.98); exercise: ICC = 0.93 (0.88-0.96)) test-retest reliabilities were observed for the SAC composite score and cTG score, respectively. CONCLUSIONS: Our DT assessment was robust to the influence of moderate-intensity exercise and demonstrated good-to-excellent test-retest reliability in a healthy collegiate sample.

More Than Skin Deep: Patient-Provider Racial and Ethnic Concordance and Discordance in Collegiate Athletics and Concussion Management.

CONTEXT: There is strong evidence that racial and ethnic disparities exist in multiple arenas of health and wellness. The causes of racial and ethnic differences in health care are multidimensional; one factor that may affect injury/illness communication, interactions, and outcomes is patient-provider racial and ethnic concordance. At present, it is unclear what role patient-provider racial and ethnic concordance and discordance plays in facilitating concussion care for collegiate athletes. OBJECTIVE: To investigate the presence of athlete-athletic trainer (AT) racial and ethnic concordance and discordance among diagnosed concussion cases and examine if racial and ethnic concordance and discordance influences time (in days) until diagnosis, symptom resolution, or return-to-sport clinical milestones in collegiate athletes. DESIGN: Retrospective cohort study. SETTING: Collegiate athletics. PATIENTS OR OTHER PARTICIPANTS: A total of 694 concussion cases (38.6% [n = 268] sustained by women, 61.4% [n = 426] sustained by men) that occurred within the 2015-2016 through 2019-2020 sport seasons at 9 institutions. MAIN OUTCOME MEASURE(S): The number of days from the date of injury to diagnosis, symptom resolution, and return to sport and from the date of diagnosis to symptom resolution and return to sport. RESULTS: Overall, 68.4% (n = 475) of concussion cases had patient-provider racial and ethnic concordance, and 31.6% (n = 219) were discordant. All concordant pairs included a White athlete and White AT. Time to diagnosis differed between the concordant and discordant groups (median [interquartile range] = 1 [0-2] versus 0 [0-1], respectively) only in the model adjusted for sex, sport type, and availability of an AT (odds ratio [95% CI] = 1.46 [1.07-1.85]). There were no other group differences. CONCLUSIONS: One-third of concussion cases had athlete-AT racial and ethnic discordance. Although this group was diagnosed with a concussion 1 day sooner than the concordant group, no differences were observed for any concussion recovery milestones. These findings suggest that patient-provider racial and ethnic concordance may play a minor role in concussion recognition or reporting but not necessarily in the management and recovery thereafter.

Computerized neurocognitive testing in the management of sport-related concussion: an update.

Since the late nineties, computerized neurocognitive testing has become a central component of sport-related concussion (SRC) management at all levels of sport. In 2005, a review of the available evidence on the psychometric properties of four computerized neuropsychological test batteries concluded that the tests did not possess the necessary criteria to warrant clinical application. Since the publication of that review, several more computerized neurocognitive tests have entered the market place. The purpose of this review is to summarize the body of published studies on psychometric properties and clinical utility of computerized neurocognitive tests available for use in the assessment of SRC. A review of the literature from 2005 to 2013 was conducted to gather evidence of test-retest reliability and clinical validity of these instruments. Reviewed articles included both prospective and retrospective studies of primarily sport-based adult and pediatric samples. Summaries are provided regarding the available evidence of reliability and validity for the most commonly used computerized neurocognitive tests in sports settings.