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Exercise training (EX) and weight loss (WL) improve lower extremity physical function (LEPF) in older overweight women; however, effects on rate of torque development (RTD) are unknown. This study aimed to determine the effects of WL + EX or WL alone on RTD, and relatedly LEPF, in overweight older women. Leg strength was assessed using isokinetic dynamometry, and RTD was calculated (RTD200 = RTD at 200 ms, RTDPeak = peak RTD, T2P = time to 1st peak). LEPF was determined via clinical functional tasks. Women (n = 44, 69.1 ± 3.6 years, 30.6 ± 4.3 kg/m2) completed a 6-month trial in EX + WL or WL groups with similar weight loss (−9.8 ± 4.2%, p > .95). EX + WL had greater improvements in (a) most LEPF tasks (p 200, compared with WL (36% vs. −16%, p = .031); no other RTD parameters differed. Changes in RTD parameters and LEPF were not related (all p > .05). RTD is responsive to EX but is not associated with LEPF in older women.

Background: An association has been identified between concussion and lower extremity musculoskeletal injury (LEMSKI) after return to sports participation. However, the collegiate student-athlete studies have relied on relatively small single-institution studies, which limits generalizability. Purpose: To assess odds of, and time to, LEMSKI after concussion in US collegiate athletes, using the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP). Study Design: Descriptive epidemiology study. Methods: Data from the NCAA ISP during the 2010-2011 through 2019-2020 athletic seasons were considered for analysis. Frequency distributions were examined for details related to the initial and subsequent injuries (injuries to bone, bursa, joint, ligament, muscle, or tendon). Multivariable logistic regression models and random-effects Poisson regression models examined odds of time loss (TL) and non–time loss (NTL) LEMSKI after concussion, as well as the time interval between initial concussion and subsequent LEMSKI in a single athletic season, or initial musculoskeletal injury (MSKI) and subsequent LEMSKI in a single athletic season. Analyses were performed separately for football and other sports. Results: A total of 31,556 initial injuries were recorded (football: 11,900; other sports: 19,656), which were followed by 0 or 1 injury in the same season. Overall, first injury type was not a significant predictor of subsequent LEMSKI, although certain contrasts yielded significant estimates. In football, the odds of NTL LEMSKI were higher after concussion than after upper extremity MSKI (UEMSKI; adjusted odds ratio [ORAdj], 1.56; 95% CI, 1.06-2.31). In football, the odds of TL LEMSKI were lower after concussion than after UEMSKI (ORAdj, 0.71; 95% CI, 0.51-0.99). No other significant effect estimates were observed for football or other sports. Conclusion: First injury type, either concussion or upper extremity, was not associated with an elevated risk of LEMSKI. Specifically, the results of this study did not identify an elevated odds of LEMSKI after a concussion. However, the authors observed greater odds of NTL LEMSKI and lower odds of TL LEMSKI in football.

Context: Aberrant movement patterns among individuals with concussion history have been reported during sport-related movement. However, the acute postconcussion kinematic and kinetic biomechanical movement patterns during a rapid acceleration–deceleration task have not been profiled and leaves their progressive trajectory unknown. Our study aimed to examine single-leg hop stabilization kinematics and kinetics between concussed and healthy-matched controls acutely (≤7 d) and when asymptomatic (≤72 h of symptom resolution). Design: Prospective, cohort laboratory study. Methods: Ten concussed (60% male; 19.2 [0.9] y; 178.7 [14.0] cm; 71.3 [18.0] kg) and 10 matched controls (60% male; 19.5 [1.2] y; 176.1 [12.6] cm; 71.0 [17.0] kg) completed the single-leg hop stabilization task under single and dual task (subtracting by 6’s or 7’s) at both time points. Participants stood on a 30-cm tall box set 50% of their height behind force plates while in an athletic stance. A synchronized light was illuminated randomly, queuing participants to initiate the movement as rapidly as possible. Participants then jumped forward, landed on their nondominant leg, and were instructed to reach and maintain stabilization as fast as possible upon ground contact. We used 2 (group) × 2 (time) mixed-model analyses of variance to compare single-leg hop stabilization outcomes separately during single and dual task. Results: We observed a significant main group effect for single-task ankle plantarflexion moment, with greater normalized torque (mean difference = 0.03 N·m/body weight; P = .048, g = 1.18) for concussed individuals across time points. A significant interaction effect for single-task reaction time indicated that concussed individuals had slower performance acutely relative to asymptomatic (mean difference = 0.09 s; P = .015, g = 0.64), while control group performance was stable. No other main or interaction effects for single-leg hop stabilization task metrics were present during single and dual task (P ≥ .051). Conclusions: Greater ankle plantarflexion torque coupled with slower reaction time may indicate stiff, conservative single-leg hop stabilization performance acutely following concussion. Our findings shed preliminary light on the recovery trajectories of biomechanical alterations following concussion and provide specific kinematic and kinetic focal points for future research.

Context: Neuromuscular function is altered acutely following concussion and theoretically linked to the subsequent postconcussion musculoskeletal injury risk. Existing research has only examined voluntary muscle activation, limiting mechanistic understanding. Therefore, our study aimed to examine voluntary and involuntary muscle activation between college-aged, concussed individuals when symptom-free and healthy matched controls. Design: Prospective, cross-sectional cohort laboratory study. Methods: Concussed and healthy participants (n = 24; 58% male, age: 19.3 [1.1] y, mass: 70.3 [16.4] kg, height: 177.3 [12.7] cm) completed the superimposed burst (SB) neuromuscular assessment on their dominant limb within 72 hours after self-reporting asymptomatic (22.4 [20.2] d postinjury). Unnormalized and bodyweight-normalized quadriceps maximal voluntary isometric contraction torque (in newton meters), unnormalized and bodyweight-normalized electrically stimulated SB torque, pain (numeric 1–10) during SB, and the central activation ratio (in percentage) were assessed via the SB. Parametric and nonparametric analyses, 95% confidence intervals (95% CIs), and Hedges g (parametric) and Spearman ρ (nonparametric) effect sizes were used to examine group differences (α = .05). Results: The maximal voluntary isometric contraction torque (concussed: 635.60 N·m [300.93] vs control: 556.27 N·m [182.46]; 95% CI, −131.36 to 290.02; P = .443; d = 0.33), SB torque (concussed: 203.22 N·m [97.17], control: 262.85 N·m [159.07]; 95% CI, −171.22 to 51.97; P = .280; d = −0.47), and central activation ratio (concussed: 72.16% [17.16], control: 70.09% [12.63]; 95% CI, −10.68 to 14.83; P = .740; d = 0.14) did not differ between the concussed and control groups regardless of bodyweight normalization (P ≥ .344). Pain during the SB was significantly higher with a medium effect for participants with a concussion versus healthy controls (concussed: median = 7, control: median = 5; P = .046; ρ = −0.42). Discussion: These findings suggest concussed participants do not have statistically altered voluntary or involuntary quadricep neuromuscular function once asymptomatic compared with controls. Therefore, the elevated postconcussion musculoskeletal injury risk may not be attributed to lower-extremity muscle activation. Concussed participants displayed greater pain perception during the SB, which suggests somatosensory or perception changes requiring further examination.

Background: The prevalence of unreported concussions is high, and undiagnosed concussions can lead to worse postconcussion outcomes. It is not clear how those with a history of undiagnosed concussion perform on subsequent standard concussion baseline assessments. Purpose: To determine if previous concussion diagnosis status was associated with outcomes on the standard baseline concussion assessment battery. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Concussion Assessment, Research, and Education (CARE) Consortium participants (N = 29,934) self-reported concussion history with diagnosis status and completed standard baseline concussion assessments, including assessments for symptoms, mental status, balance, and neurocognition. Multiple linear regression models were used to estimate mean differences and 95% CIs among concussion history groups (no concussion history [n = 23,037; 77.0%], all previous concussions diagnosed [n = 5315; 17.8%], ≥1 previous concussions undiagnosed [n = 1582; 5.3%]) at baseline for all outcomes except symptom severity and Brief Symptom Inventory–18 (BSI-18) score, in which negative binomial models were used to calculate incidence rate ratios (IRRs). All models were adjusted for sex, race, ethnicity, sport contact level, and concussion count. Mean differences with 95% CIs excluding 0.00 and at least a small effect size (≥0.20), and those IRRs with 95% CIs excluding 1.00 and at least a small association (IRR, ≥1.10) were considered significant. Results: The ≥1 previous concussions undiagnosed group reported significantly greater symptom severity scores (IRR, ≥1.38) and BSI-18 (IRR, ≥1.31) scores relative to the no concussion history and all previous concussions diagnosed groups. The ≥1 previous concussions undiagnosed group performed significantly worse on 6 neurocognitive assessments while performing better on only 2 compared with the no concussion history and all previous concussions diagnosed groups. There were no between-group differences on mental status or balance assessments. Conclusion: An undiagnosed concussion history was associated with worse clinical indicators at future baseline assessments. Individuals reporting ≥1 previous undiagnosed concussions exhibited worse baseline clinical indicators. This may suggest that concussion-related harm may be exacerbated when injuries are not diagnosed.

To describe concussion characteristics among general college students and compare postinjury outcomes to intercollegiate student athletes.Retrospective cohort.Large university in the Southeast region of the United States.A total of 179 (N=179) college students' (female=120; 67.0%; 23.9±3.9 years) and 49 athletes' (female=28, 57.1%;19.3±1.3 years) medical records were examined. Participants self-reported injury mechanism, health history information, and completed clinical assessments acutely (7 days postinjury).Descriptive statistics were calculated for each group. Concussion outcomes between students with and without certain health history diagnoses were assessed using separate t tests. We conducted univariate regression analyses to determine if sex, age, and time from concussion to first clinical assessment were significant predictors of clinical outcomes. Statistically significant variables were included as covariates in a series of 1-way analyses of covariance to identify differences in balance, symptom severity, total symptom presence, and neurocognitive domain performance between students and athletes. Fisher exact tests were used to compare health history information between groups (α0.05).Among students, 24% reported sustaining a concussion while participating in recreational sports, and 27% of impacts occurred to the back of the head. Students had higher proportions of headache, migraine, anxiety, and depression (P.05). Students reported greater total symptom presence (P=.006) and performed worse on the computerized neurocognitive test domain score for complex attention (P=.015) relative to athletes.These findings highlight the need for better access to medical care for non- National Collegiate Athletic Association sanctioned athletes because of a large proportion of concussions in the student sample being sustained during sports participation. Identifying common injury mechanisms can provide clinicians with powerful information to improve evaluation and treatment models.

A tandem gait (TG) assessment is recommended post-concussion. There is limited research examining psychometric properties of TG assessments.The purpose of this study was to determine TG inter-trial and one-week test-retest reliability. We hypothesized TG would yield moderate to good reliability, times would improve across trials/sessions and average scores would have higher reliability.Reliability study.Research laboratory.Sixty participants (36 females, age: 20.4 ± 1.8y) completed ten TG trials on two occasions.Dependent variables included number of normal trials (participants stayed on the line, heel and toe touched on every step, and they avoided touching an examiner/object) and times for each trial. We analyzed inter-trial reliability using a one-way analysis of covariance and intraclass correlation coefficients (ICC), and test-retest reliability using dependent samples t-tests and ICCs.At the first testing session, there were significant differences in times across seven trials (FThere are practice effects when administering multiple TG trials, but scores stabilize after the fifth trial. There are practice effects associated with multiple administrations of the TG test, but outcomes using times for four or five trials have adequate one-week test-retest reliability in healthy physically active young adults. This article is protected by copyright. All rights reserved.

Previous research among adolescents has shown differences in symptoms and neurocognitive performance between sport-related (SRC) and motor vehicle crash (MVC) concussion mechanisms. Limited research has focused on young adults. The purpose of our study was to compare symptoms, balance, and neurocognitive performance between SRC and MVC mechanisms in young adults. Forty-three (58.1% female, age = 25.5 ± 3.2 years, days since concussion = 12.8 ± 12.7) and 26 (76.9% female, age = 24.1 ± 5.6 years, days since concussion = 12.6 ± 8.3) individuals with an SRC and MVC mechanism, respectively, participated. Primary outcome measures included the total number, severity, cluster (disorientation, migraine, lethargy, and affective) of post-concussion symptoms endorsed, Balance Error Scoring System (BESS), and CNS Vital Signs scores. Clusters are subgroups of symptoms used for targeted rehabilitation. We used independent t-tests and Mann–Whitney U tests to compare symptoms, BESS, and neurocognitive performance. Cliff’s Delta effect size was interpreted as negligible (p-range = 0.112–0.991). Participants with an MVC mechanism reported a greater number of total post-concussion symptoms (p = 0.025, Cliff’s Delta = 0.32) and a more severe affective symptom cluster (p = 0.010, Cliff’s Delta = 0.37). There were no group differences for BESS or neurocognitive performance after correcting for multiple comparisons. The MVC mechanism resulted in a greater total symptom burden relative to the SRC mechanism. Medical practitioners and individuals experiencing a concussion should know that concussions are heterogeneous within and across various mechanisms.

Context: Reaction time is commonly assessed postconcussion through a computerized neurocognitive battery. Although this measure is sensitive to postconcussion deficits, it is not clear if computerized reaction time reflects the dynamic reaction time necessary to compete effectively and safely during sporting activities. Functional reaction time assessments may be useful postconcussion, but reliability must be determined before clinical implementation. Objective: To determine the test–retest reliability of a functional reaction time assessment battery and to determine if reaction time improved between sessions. Design: Cohort. Setting: Laboratory. Participants: Forty-one participants (21 men and 20 women) completed 2 time points. Participants, on average, were 22.5 (2.1) years old, 72.5 (11.9) cm tall, had a mass of 71.0 (13.7) kg, and were mostly right leg and hand dominant (92.7%). Interventions: Participants completed 2 clinical reaction time tests (computerized Stroop and drop stick) and 5 functional reaction time tests (gait, jump landing, single-leg hop, anticipated cut, and unanticipated cut) across 2 sessions. Drop stick and functional reaction time assessments were performed in single (motor task only) and dual task (motor task with cognitive task). Main Outcome Measures: Reaction time (in seconds) was calculated during all assessments. Test–retest reliability was determined using 2-way mixed-effects intraclass correlation coefficients (3, k). Paired samples t tests compared mean reaction time between sessions. Results: Test–retest reliability was moderate to excellent for all reaction time outcomes (intraclass correlation coefficients [3, k] range = .766–.925). Several statistically significant between-session mean differences were observed, but effect sizes were negligible to small (d range = 0.05–0.44). Conclusions: The functional reaction time assessment battery displayed similar reliability to the standard computerized reaction time assessment battery and may provide important postinjury information, but more research is needed to determine clinical utility.

Our purpose was to investigate the reliability and minimal detectable change characteristics of a smartphone-based assessment of single- and dual-task gait and cognitive performance. Uninjured adolescent athletes (n = 17; mean age = 16.6, SD = 1.3 y; 47% female) completed assessments initially and again 4 weeks later. The authors collected data via an automated smartphone-based application while participants completed a series of tasks under (1) single-task cognitive, (2) single-task gait, and (3) dual-task cognitive-gait conditions. The cognitive task was a series of continuous auditory Stroop cues. Average gait speed was consistent between testing sessions in single-task (0.98, SD = 0.21 vs 0.96, SD = 0.19 m/s;P = .60;r = .89) and dual-task (0.92, SD = 0.22 vs 0.89, SD = 0.22 m/s;P = .37;r = .88) conditions. Response accuracy was moderately consistent between assessments in single-task standing (82.3% accurate, SD = 17.9% vs 84.6% accurate, SD = 20.1%;P = .64;r = .52) and dual-task gait (89.4% accurate, SD = 15.9% vs 85.8% accurate, SD = 20.2%;P = .23;r = .81) conditions. Our results indicate automated motor-cognitive dual-task outcomes obtained within a smartphone-based assessment are consistent across a 1-month period. Further research is required to understand how this assessment performs in the setting of sport-related concussion. Given the relative reliability of values obtained, a smartphone-based evaluation may be considered for use to evaluate changes across time among adolescents, postconcussion.

Background This study determined the effect of video-verified collision characteristics on head impact magnitudes in male youth tackle football. Methods Participants (n = 23, age = 10.9 ± 0.3 years, height = 150.0 ± 8.3 cm, mass = 41.6 ± 8.4 kg) wore Triax Sim-G sensors throughout the fall 2019 season. Ten filmed games were used to identify nine different collision characteristics: mechanism, preparedness, head direction, struck versus striking activity, stance, play type, closing distance, penalty, and quarter. Random-effects general linear models and Cohen d effect sizes were used to examine differences in log-transformed peak linear (PLA; g) and rotational (PRA; rad/s2) accelerations across characteristics. The 10 games produced 533 total video-verified impacts and 23.2 ± 7.2 impacts per athlete. Results PLA (P range: 0.107 to 0.923) and PRA (P range: 0.057 to 0.768) did not differ across characteristics. Struck players (3370 rads/s2, 95% confidence interval [CI] = 2986 to 3808) had a small effect for higher PRA compared with striking players (3037 rads/s2, 95% CI = 2713 to 3404, d = 0.251), but negligible effect for simultaneous struck-striking players (3340 rad/s2, 95% CI = 2945 to 3792, d = 0.018). Fourth quarter impacts (3490 rads/s2, 95% CI = 3083 to 3951) had a small effect for higher PRA compared with first (2945 rads/s2, 95% CI = 2596 to 3337, d = 0.404), second (3196 rads/s2, 95% CI = 2832 to 3604, d = 0.219), and third quarters (3241 rads/s2, 95% CI = 2841 to 3699, d = 0.144). Conclusion Youth tackle football characteristics did not significantly affect head impact magnitudes during games. More research is needed to explore additional factors that could be modified for sport safety rather than mitigating impact mechanism.

Context Post-concussion reaction time deficits are common, but existing assessments lack sport-related applicability. We developed the Standardized Assessment of Reaction Time (StART) to emulate simultaneous cognitive and motor function demands in sport, but its reliability is unestablished. Objective To determine the intra-rater, inter-rater, and test-retest reliability of StART, and examine the dual-task effect, time effect, and relationships between StART and computerized and laboratory-based functional reaction time assessments. Design Prospective cohort study. Setting Clinical laboratory. Patients or Other Participants 20 healthy, physically active participants (age: 20.3±1.8 years; 60% female; 75% no concussion history). Main Outcome Measures Participants completed StART, computerized reaction time (Stroop task via CNS Vital Signs), and laboratory-based jump landing and cutting reaction time under single-task and dual-task (subtracting by 6's or 7's) cognitive conditions at two testing sessions a median 7 days apart. We used Intraclass correlation coefficients, repeated-measure ANOVAs, and Pearson r correlations to address our aims. Results Overall good to strong inter-rater (ICC2,k range:0.83–0.97), intra-rater (ICC3,k range:0.91–0.98), and test-retest reliability (ICC3,k range:0.69–0.89) were observed. A significant reaction time assessment by cognitive condition interaction was present (p=0.018,ηp2=0.14), with StART having the largest dual-task effect. Main time effects for dual-task conditions were observed across all reaction time assessments (mean difference: −25ms;p=0.026,ηp2=0.08) for improved performance at the second testing session. No StART outcomes correlated with computerized reaction time (p>0.05), although some StART outcomes correlated with single-task (r-range:0.42–65) and dual-task (r-range:0.19–0.50) laboratory cutting reaction time. Conclusions StART demonstrated overall reliable performance relative to other reaction time measures. Reliability coupled with a strong dual-task effect indicates StART is a valid measure for examining functional reaction time, and may have future utility for sport-related concussion return to play decision-making.

Shumski, EJ, Lempke, LB, Johnson, RS, Oh, J, Schmidt, JD, and Lynall, RC. Jump height and hip power decrease during cognitive loading regardless of sex: implications for sport performance metrics. J Strength Cond Res XX(X): 000-000, 2022-Sex and cognitive loading separately influence jumping performance. However, it is unknown how cognitive loading influences jump performance and how sex and cognitive loading interact. The purpose of our study was to determine if an interaction existed between sex and cognitive loading for the dependent variables jump height, ground contact time, reactive strength index, vertical stiffness, impulse, and lower extremity joint power during a double limb drop vertical jump. Twenty-one male (23.2 ± 2.5 years, 180.8 ± 8.4 cm, 80.4 ± 10.2 kg) and 20 female (21.7 ± 1.0 years, 163.7 ± 8.2 cm, 61.2 ± 9.4 kg) physically active individuals participated. Subjects jumped from a 30 cm box placed 50% of their height away from 2 force plates under single-task and dual-task (serial 6s or 7s) conditions. Separate 2 × 2 analyses of variance were used for all dependent variables (α = 0.05) with Bonferroni post hoc mean differences and 95% confidence intervals (CIs). There were no significant interactions for any outcomes (p ≥ 0.190). Condition main effects demonstrated subjects jumped significantly higher (1.84 cm, 95% CI = 0.68-3.01, d = 0.26, p = 0.003) and with greater hip power (0.29 Watts·BW-1·HT-1, 95% CI = 0.04-0.54, d = 0.21, p = 0.025) during single task compared with dual task. Sex main effects revealed males jumped higher (9.88 cm, 95% CI = 7.00-12.77, d = 2.17, p0.001), with greater reactive strength index (0.29, 95% CI = 0.17-0.41, d = 1.52, p0.001), greater ankle power (3.70 Watts·BW-1·HT-1, 95% CI = 2.26-5.13, d = 1.64, p0.001), and greater knee power (5.00 Watts·BW-1·HT-1, 95% CI = 3.25-6.75, d = 1.82, p0.001) compared with females. Jump performance is influenced by sex and dual-task conditions but not their interaction. To optimize jumping performance, testing should be completed without distractions (single task) to decrease cognitive loading.

Background: Youth flag football participation has rapidly grown and is a potentially safer alternative to tackle football. However, limited research has quantitatively assessed youth flag football head impact biomechanics. Purpose: To describe head impact biomechanics outcomes in youth flag football and explore factors associated with head impact magnitudes. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We monitored 52 player-seasons among 48 male flag football players (mean ± SD; age, 9.4 ± 1.1 years; height, 138.6 ± 9.5 cm; mass, 34.7 ± 9.2 kg) across 3 seasons using head impact sensors during practices and games. Sensors recorded head impact frequencies, peak linear ( g) and rotational (rad/s2) acceleration, and estimated impact location. Impact rates (IRs) were calculated as 1 impact per 10 player-exposures; IR ratios (IRRs) were used to compare season, event type, and age group IRs; and 95% CIs were calculated for IRs and IRRs. Weekly and seasonal cumulative head impact frequencies and magnitudes were calculated. Mixed-model regression models examined the association between player characteristics, event type, and seasons and peak linear and rotational accelerations. Results: A total of 429 head impacts from 604 exposures occurred across the study period (IR, 7.10; 95% CI, 4.81-10.50). Weekly and seasonal cumulative median head impact frequencies were 1.00 (range, 0-2.63) and 7.50 (range, 0-21.00), respectively. The most frequent estimated head impact locations were the skull base (n = 96; 22.4%), top of the head (n = 74; 17.2%), and back of the head (n = 66; 15.4%). The combined event type IRs differed among the 3 seasons (IRR range, 1.45-2.68). Games produced greater IRs (IRR, 1.24; 95% CI, 1.01-1.53) and peak linear acceleration (mean difference, 5.69 g; P = .008) than did practices. Older players demonstrated greater combined event–type IRs (IRR, 1.46; 95% CI, 1.12-1.90) and increased head impact magnitudes than did younger players, with every 1-year age increase associated with a 3.78 g and 602.81-rad/s2 increase in peak linear and rotational acceleration magnitude, respectively ( P≤ .005). Conclusion: Head IRs and magnitudes varied across seasons, thus highlighting multiple season and cohort data are valuable when providing estimates. Head IRs were relatively low across seasons, while linear and rotational acceleration magnitudes were relatively high.

To identify factors affecting performance on the tandem gait test in healthy, physically active adults.Cross-sectional.Participants completed the tandem gait test according to Sport Concussion Assessment Tool 3 (SCAT3) guidelines. Dependent variables included time for best trial (initial 3m, turn, final 3m and total) and whether the trial was "pass" or "fail". Independent variables included sex, concussion history, foot length, height and total number of trials.55% (35/64) of participants passed the first trial of the tandem gait test; 19% (12/64) had a best time14s. Sex and concussion history did not affect performance (p0.05). There were no differences in turn times for those with and without a history of concussion (t=0.26, p=0.80). The number of trials was not significantly correlated with best time (þ=-0.04, p=0.74). There were low (þ=-0.31) to negligible (þ0.30) correlations between foot length, height and all portions of the test. There was more variability in times for the turn (COV=27%) than during the straight portions (COV=18%).Current recommendations for the tandem gait test led to a high false-positive rate in healthy, physically active adults. Sex, concussion history, number of trials and foot length had little to no influence on scores on the test. Turning times were more variable than times on the straight portions of the test. Clinicians may use these results as a guideline when interpreting performance on the tandem gait test in healthy physically active adults.

We report on hyperbaric oxygen (HBO2) therapy used to improve postinjury outcomes in eight acutely concussed high school student-athletes (5 males, 3 females, mean age = 16.0 ± 1.2 years). Patients were randomly assigned into one of three intervention groups: (a) HBO2 therapy; (b) hyperbaric therapy with compressed medical-grade air (HBA); or (c) normobaric 100% O2 therapy. All patients completed five 1-hr treatments within the first 10 days following his or her concussion. Main outcome measures included mental status examination, symptom burden, and the number of days from injury until the physician permitted the student-athlete to return to activity. Patients receiving HBO2 treatment experienced the greatest absolute symptom reduction over the five treatment sessions. No meaningful differences were found in mental status examination. All participants returned to activity in a similar timeframe. HBO2 therapy may be an effective option for the acute treatment of postconcussion symptoms, particularly in young athletes presenting with a high symptom burden.

Context Certified athletic therapists in Ireland and Canada serve essential concussion assessment and management roles, but their healthcare practices and concussion knowledge are unestablished. Objective To examine Irish and Canadian athletic therapist cohorts: 1) concussion knowledge, 2) current concussion assessment and management techniques across all job settings, and 3) concussion assessment and management practices associations with years of clinical experience and highest degree attained. Design Cross-sectional cohort. Setting Online survey. Patients or Other Participants Licensed Irish (49.7%;n=91/183) and Canadian (10.1%;n=211/2,090) athletic therapists. Main Outcome Measures Athletic therapists completed an online survey assessing their demographics, concussion knowledge (symptom recognition, patient-clinician scenarios), annual concussions assessed, and assessment and return-to-play (RTP) measures using a modified, previously validated survey. Symptom recognition consisted of 20 (8 true, 12 false) signs and symptoms recognition questions scored as total correct. Descriptive statistics and odds ratios (OR) were used to examine survey responses where appropriate. Results Irish (86.8%;n=46/53) and Canadian (93.4%;n=155/166) athletic therapists indicated RTP guidelines as the most common method for determining RTP. Symptom recognition was 72.8±17.0% among Irish and 76.6±17.0% among Canadian athletic therapists. Irish (91.2%;n=52/57) and Canadian (95.3%;n=161/178) athletic therapists reported standardized sideline assessments as the most common concussion assessment method. Irish and Canadian athletic therapists' two-domain (Irish:38.6%[n=22/57]; Canadian:73.6%[n=131/178]) and three-domain (Irish:3.5%[n=2/57]; Canadian:19.7%[n=35/178]) minimum assessments (i.e. symptoms, balance, and/or neurocognitive) were not associated with education or clinical experience (p≥0.068), except for Canadian athletic therapists with Master's degrees having greater odds of completing two-domain assessments at initial evaluation than those with Bachelor's degrees (OR[95%CI]=1.8[1.41–1.95]). Conclusions Irish and Canadian athletic therapists demonstrated similar concussion knowledge to prior research; however, the majority did not fully adhere to international consensus concussion assessment guidelines as evidenced by low two- and three- domain assessment use. Athletic therapists should aim to implement multidimensional concussion assessments to ensure optimal healthcare practices and patient safety.

Balance impairments may suggest somatosensory disruption beyond concussion clinical recovery, but somatosensory subsystems have never been directly assessed. Our objective was to examine somatosensory function between individuals with a concussion and healthy matched-controls at acute (7 days) and asymptomatic (72 hours of being symptom-free) time points.Laboratory.Participants with a concussion and matched controls (n = 24; 58% male, age: 19.3 ± 1.1 years, mass: 70.3 ± 16.4 kg, height: 177.3 ± 12.7 cm).Prospective cohort.Somatosensory assessments on the dominant limb at both time points included: (1) plantar touch sensation threshold via Semmes-Weinstein monofilaments, (2) plantar pressure pain threshold via algometry, and (3) knee absolute passive joint repositioning (PJR) error via Biodex across 3 arcs (105°-75°, 30°-60°, 90°-45° knee-flexion). We used mixed-model analyses of variance, post hoc Tukey honestly significant difference t tests with mean difference, 95% CI, and Hedges' g effect sizes to examine outcomes.Touch sensation had a group effect with the concussion cohort needing 0.95 grams of force (gf) more relative to controls (95% CI: 0.03 to 1.87; P = .043). No touch sensation interaction was present, but medium and large effects were observed for greater gf needed among the concussed cohort at the acute (1.11 gf; 95% CI: 0.17 to 2.05; g = 0.96) and asymptomatic time points (0.79 gf; 95% CI: -0.15 to 1.73; g = 0.73). No plantar pressure pain threshold effects were observed (P ≥ .311), with negligible pressure difference magnitudes at the acute (0.26 pound force [lbf]/cm2; 95% CI: -1.54 to 2.06; g = 0.13) and medium magnitudes at the asymptomatic time points (0.99 lbf/cm2; 95% CI: -0.81 to 2.80; g = 0.42) for the concussed cohort needing more pressure to detect pain. The 30° to 60° PJR had a time effect, with asymptomatic time point having 3.12° better accuracy (95% CI: 1.23° to 5.02; P = .002). The concussed cohort had small-to-medium magnitude differences relative to controls at the acute time point for PJR during 105° to 75° (0.89°; g = 0.30) and 90° to 45° (0.62°; g = 0.17), but not 30° to 60° (-1.75°; g = -0.40).Individuals with a concussion exhibited large effects for diminished plantar touch sensation and small to medium effects for inhibited plantar pressure pain sensation compared with controls, which may indicate altered somatosensory function. Negligible PJR differences suggest knee joint position sense is not altered post-concussion. Pre- and postconcussion examination is warranted to understand causal somatosensory mechanisms.

IntroductionMusculoskeletal injury (MSKI) risk is increased following mild traumatic brain injury (mTBI). Increased MSKI risk is present up to 2 years following post-mTBI return-to-duty/activity relative to both non-mTBI peers and to their pre-mTBI selves across a range of populations, including military service members, and professional, college and high school athletes. Despite the well documented increased post-mTBI MSKI risk, the underlying neuromuscular mechanisms contributing to this increased risk have yet to be definitively determined. A number of potential mechanisms have been suggested (eg, aberrant kinematics, dynamic balance impairments, lower voluntary muscle activation), but none have been confirmed with a comprehensive, prospective study. This study aims to: (1) elucidate the neuromuscular control mechanisms following mTBI that contribute to increased MSKI risk, and (2) prospectively track patient outcomes (up to 12 months; MSKI occurrences and patient-reported outcomes (PRO)).Methods and analysisThis is a multicentre prospective, case-matched control observational study to identify deficiencies in neuromuscular function following mTBI that may contribute to increased MSKI risk. Participants (aim to recruit 148, complete data collection on 124) will be classified into two cohorts; mTBI and control. All participants will undergo longitudinal (initial, 6 weeks post-initial, 12 weeks post-initial) comprehensive three-dimensional biomechanical (jump-landing; single leg hop; cut; gait), neuromuscular (interpolated twitch technique, muscular ramp contraction) and sensory (joint repositioning; light touch sensation) assessments to elucidate the underlying neuromuscular control mechanisms post-mTBI that may contribute to increased MSKI. Occurrences of MSKI and PROs (National Institutes of Health Patient-Reported Outcome Measurement Information System: Physical Function, Pain Interference, Depression, Anxiety; Brief Resilience Scale; Tampa Scale of Kinesiophobia), will be tracked monthly (up to 1 year) via electronic data capture platforms.Ethics and disseminationThe study received approval from the Walter Reed National Military Medical Center Institutional Review Board. Results will be made available to the associated funding agency and other researchers via conference proceedings and journal articles.Trial registration numberNCT05122728.

In equipment-heavy sports, there is a growing need to evaluate players in the condition in which they participate. However, the psychometric properties of the Balance Error Scoring System (BESS) while wearing skates remains unknown. Seventy-four adolescent male hockey players completed the BESS with and without skates. A subset was reevaluated at the conclusion of the season. The BESS while wearing skates resulted in a mean of 15 more total errors than the traditional administration (t73 = 14.94, p

Recent literature has indicated altitude may be a protective factor for concussion but it is unknown whether altitude or heat index affects recovery. To examine whether on-field heat index and altitude at the time of injury alter acute (

PURPOSE Sport-related head impact biomechanics research has been male-centric and focused primarily on American football and ice hockey, which do not address popular sports in which both sexes participate. The purpose of this study was to quantify college female and male lacrosse and soccer head impact biomechanics. METHODS Head impact biomechanics were collected from college lacrosse and soccer players across two Division 1 college athletic programs (96 female athletes, 141 male athletes; age, 19.8 ± 1.3 yr; height, 174.8 ± 9.2 cm; mass, 72.4 ± 11.7 kg). We deployed helmetless head impact measurement devices (X2 Biosystems xPatch) before each event. Peak linear and rotational accelerations were log-transformed for random intercepts general linear mixed models, and subsequently categorized based on impact magnitude for additional categorical analyses. RESULTS Most linear (69.4%) and rotational (72.3%) head impact accelerations sustained by our study cohort were categorized as mild. On average, male athletes sustained impacts with higher linear accelerations than females (P = 0.04), and lacrosse athletes sustained higher linear acceleration impacts than soccer athletes (P = 0.023). Soccer athletes sustained significantly higher-magnitude impacts during competitions versus practices (linear, P < 0.001, rotational, P < 0.001), whereas lacrosse athletes sustained higher-magnitude impacts during practices versus competition (linear, P < 0.001; rotational, P < 0.001). Male athletes sustained higher accelerations in competitions versus practice (linear, P = 0.004; rotational, P < 0.001), whereas female athletes sustained higher accelerations in practice versus competitions (linear, P < 0.001; rotational, P = 0.02). There were no interactions between sex and sport on impact magnitude. CONCLUSIONS Male athletes and lacrosse athletes experience higher-magnitude head impacts. Given the limited literature in this area, future research should continue characterizing head impact biomechanics in women's and nonhelmeted sports as well as validate nonhelmeted head impact technologies.

Context: With growing concerns surrounding exposure to head impacts in youth tackle football, it is essential that parents and players understand the exposure level when consenting/assenting to participate. Objective: We aimed to determine whether youth football parents and players could estimate on-field head impact frequency, severity, and location. Design: Prospective Cohort Study Setting: On-field Patients or Other Participants: We administered a 10-question head impact estimation tool to parents (N=23; 36.5, 95% CI: 31.7, 37.3) and players (N=16; Age: 11.1, 95%CI: 10.3,11.8). Main Outcome Measures: Player on-field head impact exposure was captured using the Triax SIM-G system. We determined the accuracy between parent and players estimates relative to on-field head impact exposures using kappa and weighted kappa values. Results: Youth tackle football parents and players do not accurately estimate on-field head impact frequency (kappa range:−0.09–0.40), severity (kappa range: −0.05–0.34), or location (kappa range: −0.30–0.09). Parents and players overestimated head impact frequency in practices, but underestimated the frequency in games. Parents and players overestimated head impact severity, particularly in games. Most parents and players underestimated the number of head impacts to the top of the head, particularly during practices. Conclusions: Underestimations in head impact frequency in games and to the top of the head suggest that informed consent processes aimed at educating parents and players should be improved. Overestimations in head impact frequency in practices and severity may explain declining rates of youth tackle football participation.

BackgroundConcussion education programs have been implemented across sport associations to improve concussion recognition and reporting intentions. Despite widespread implementation, no studies have examined the influence of concussion knowledge on reporting intentions in collegiate athletes.PurposeTo (1) examine if concussion knowledge is a predictor of concussion reporting intentions and (2) identify concussion knowledge differences based on sex, age, and years of sport eligibility remaining in collegiate athletes.MethodsOne-hundred five collegiate athletes across 3 universities completed an online reporting intentions survey (consisting of indirect and direct reporting intentions) and 2 online concussion knowledge surveys (indirect knowledge agreement and direct knowledge assessment [comprised of signs/symptoms recognition and general knowledge]) across a four-month period. General linear models were used to test whether concussion knowledge outcome scores predicted indirect and direct reporting intentions, and if concussion knowledge differed within demographic factors.ResultsIndirect knowledge agreement explained 12.9% of direct reporting intentions variability (R2 = 0.129, F3, 73 = 3.61, p = 0.017). Knowledge did not predict indirect reporting intentions (p = 0.152). Females demonstrated greater signs and symptoms recognition than males (females: 79.1% ± 12.3% vs males: 73.0% ± 13.5%, p = 0.017, d = 0.47). Knowledge outcomes did not differ between sexes (p ≥ 0.117), age groups (p ≥ 0.491), or years of eligibility remaining (p ≥ 0.393). Neither age (p ≥ 0.491) nor years of sport eligibility remaining (p ≥ 0.393) affected concussion knowledge outcome measures.ConclusionsConcussion knowledge has limited predictive capabilities for determining reporting intentions. Although statistically significant, concussion knowledge sex differences may not be clinically meaningful. Clinicians should take caution in relying heavily on knowledge interventions to influence concussion reporting. Future studies should examine the role psychosocial factors play in improving concussion reporting.

PURPOSE This study aimed to examine the association between clinical and functional reaction time (RT) assessments with and without simultaneous cognitive tasks among healthy individuals. METHODS Participants (n = 41, 49% female; 22.5 ± 2.1 yr; 172.5 ± 11.9 cm; 71.0 ± 13.7 kg) completed clinical (drop stick, Stroop) and functional (gait, jump landing, single-leg hop, anticipated cut, unanticipated cut) RT assessments in random order. All RT assessments, except Stroop and unanticipated cut, were completed under single- (movement only) and dual-task conditions (movement and subtracting by 6s or 7s). Drop stick involved catching a randomly dropped rod embedded in a weighted disk. Stroop assessed RT via computerized neurocognitive testing. An instrumented walkway measured gait RT when center-of-pressure moved after random stimulus. All other functional RT assessments involved participants jumping forward and performing a vertical jump (jump landing), balancing on one leg (single-leg hop), or a 45° cut in a known (anticipated cut) or unknown (unanticipated cut) direction. RT was determined when the sacrum moved following random visual stimulus. Pearson correlation coefficients and a 5 × 2 repeated-measures ANOVA compared RT assessments and cognitive conditions. RESULTS Stroop RT outcomes did not significantly correlate with functional RT assessments (r range = -0.10 to 0.24). A significant assessment by cognitive task interaction (F4,160 = 14.01; P < 0.001) revealed faster single-task RT among all assessments compared with dual-task (mean differences, -0.11 to -0.09 s; P < 0.001), except drop stick (P = 0.195). Single-leg hop (0.58 ± 0.11 s) was significantly slower compared with jump landing (0.53 ± 0.10 s), anticipated cut (0.49 ± 0.09 s), gait (0.29 ± 0.07 s), and drop stick (0.21 ± 0.03 s; P values ≤ 0.001). Dual-task assessments were significantly slower than single-task assessments (mean difference, 0.08 s; P < 0.001). CONCLUSIONS Clinical and functional RT assessments were not correlated with each other, suggesting that sport-like RT is not being assessed after concussion. Functional and dual-task RT assessments may add clinical value and warrant further exploration after concussion.

Context Athletic trainers (ATs) are heavily involved in concussion assessment and return-to-play (RTP) decision making. Despite ATs' crucial role, few researchers have directly examined ATs' knowledge of concussions or whether concussion knowledge or clinical experience affects clinical concussion-management practices. Objective To determine the overall concussion knowledge of ATs and whether concussion knowledge and clinical experience affect concussion-assessment and -management practices. Design Cross-sectional study. Setting Online survey. Patients or Other Participants Random convenience sample of 8725 (15.0% response rate [1307/8725]; certified, 14.8 ± 10.6 years) ATs surveyed from the National Athletic Trainers' Association membership. Main Outcome Measure(s) The survey collected demographics, concussion-assessment and -management tools used, and concussion knowledge (patient-clinician scenarios, signs and symptoms recognition). We used multiple logistic regression models to determine the odds ratios (ORs) for using assessment and management tools based on signs and symptoms recognition and years of clinical experience. Results The ATs correctly identified 78.0% ± 15.1% of concussion signs and symptoms. Approximately 46% (357/770) of ATs indicated an athlete could RTP if the athlete stated he or she had a “bell rung.” Every additional year of clinical experience decreased the odds of using standardized sideline-assessment tools by 3% (OR = 0.97, 95% Confidence Interval [CI] = 0.95, 0.99). The odds of using standardized sideline tools (OR = 0.98, 95% CI = 0.96, 0.99) and symptom checklists (OR = 0.98, 95% CI = 0.97, 0.99) for RTP assessment were significantly decreased for each additional year of clinical experience. No other tools used for RTP assessment were influenced by signs and symptoms recognition (P ≥ .136) or clinical experience (P ≥ .158). Conclusions The ATs with greater clinical experience had lower odds of using concussion-assessment and -management tools. Athletic trainers should frequently review and implement current consensus guidelines into clinical practice to improve concussion recognition and prevent improper management.

Concussion education have served as a keystone for improving concussion reporting. Numerous factors affecting concussion reporting have been explored; however, the role of socioeconomic status (SES) in reporting has not been established. We examined the influence of SES and academic achievement (high-school grade point average [HS-GPA] and American College Testing [ACT] composite scores) on athletes’ concussion-reporting intentions and behaviors. A cross-sectional study was employed among 191 athletes (94 female; age 19.3 ± 1.2 years). Athletes reported SES metrics (parental education and occupation, household income, HS-GPA, and ACT composite score) prior to their athletic season and completed a survey assessing symptom- and concussion-reporting intentions. Symptom- and concussion-reporting behaviors were assessed among athletes who experienced a concussion within the past year. SES was determined using the Hollingshead Four-Factor Index grouping athletes into SES strata. Athletes were grouped into low/high categories for academic achievement and household income variables. The 191 athletes were included for symptom- and concussion-reporting intentions analyses, while 46 and 41 were included for symptom- and concussion-reporting behavior, respectively. Nonparametric statistics with false discovery rate adjusted p values were employed. We found symptom- and concussion-reporting intentions, and symptom- and concussion-reporting behaviors were not significantly different based on SES strata (all p values ≥.64), household income (all p values ≥.64), HS-GPA (all p values ≥.24), or ACT scores (all p values ≥.25). Overall, SES and academic achievement may not play a role in understanding concussion reporting among middle- to high-SES collegiate athletes. Implementing policies targeting certain SES and academic levels might be an ineffective health care strategy for increasing reporting.

Reaction time (RT) deficits are reported following concussion, but it is unknown when these deficits normalize to pre-injury status. It is also unclear how factors such as RT measurement technique and participant characteristics influence post-concussion RT. The purpose of this systematic review and meta-analysis was to (1) characterize acute post-concussion (0–3 days) RT impairments, (2) examine RT recovery over time, and (3) explore moderating factors related to acute RT impairment following concussion. Database searches (PubMed, CINAHL, EBSCOhost) were conducted according to PRISMA guidelines for articles published in English from January 2002 to March 2019. Studies compared baseline-to-post-injury RT within individuals (within-subject) and/or RT in concussed individuals to non-concussed controls (between-subject). Sixty studies met inclusion criteria, reporting on a total of 9688 participants with 214 discrete RT effects (Hedges’ d; between-subject: N = 29, k = 129; within-subject: N = 42, k = 85). Of the 214 effects, 93 occurred in the acute (0–3 days) post-injury timeframe (k = 47 between-subject). Numerous demographic [sex, age, concussion history, population type (athlete, military, and general population), athlete level (high school, college), and sport], and method-based (RT test and measure type, computerized neurocognitive testing platform, concussion definition, and time post-injury) moderators were examined for mean effect influence. Mixed-effects multi-level modeling with restricted-maximum-likelihood estimation was used to account for nested effects and high heterogeneity for the pooled effect size (D+). Significant medium-magnitude RT deficits were observed acutely for between- (D+ = − 0.7279, 95% CI − 0.9919, − 0.4639, I2 = 88.66, p

Context Lower extremity musculoskeletal (LEMSK) injury may be more prevalent among those with a history of sport-related concussion (SRC). Objective To investigate the relationship between baseline postural control metrics and the LEMSK injury incidence in National Collegiate Athletic Association Division I student-athletes with a history of SRC. Setting National Collegiate Athletic Association Division I athletes. Design Cohort study. Patients or Other Participants Of 84 total athletes (62 males), 42 had been previously diagnosed with an SRC, and 42 were matched controls based on age, sex, height, weight, and sport. Main Outcome Measure(s) During the preseason baseline evaluation, all participants performed 3 trials of eyes-open and eyes-closed upright quiet stance on a force platform. Medical charts were assessed for all the LEMSK injuries that occurred from preseason baseline to 1 year later. Center-of-pressure data in the anteroposterior and mediolateral directions were filtered before we calculated root mean square and mean excursion velocity; the complexity index was calculated from the unfiltered data. Factorial analysis-of-variance models were used to examine differences between groups and across conditions for root mean square; mean excursion velocity, complexity index, and tests of association to examine between-groups LEMSK differences; and logistic regression models to predict LEMSK. Results Concussion history and injury incidence were related in the SRC group (P = .043). The complexity index of the SRC group was lower with eyes closed (14.08 ± 0.63 versus 15.93 ± 0.52) and eyes open (10.25 ± 0.52 vs 11.80 ± 0.57) in the mediolateral direction than for the control participants (P < .05). Eyes-open root mean square in the mediolateral direction was greater for the SRC group (5.00 ± 0.28 mm) than the control group (4.10 ± 0.22 mm). Logistic regression models significantly predicted LEMSK only in control participants. Conclusions These findings may suggest that LEMSK after SRC cannot be predicted from postural-control metrics at baseline.

PURPOSE This study aimed to identify clinical predictors of postconcussion subsequent musculoskeletal (MSK) injuries. METHODS We recruited 66 National Collegiate Athletic Association intercollegiate student-athletes with a diagnosed concussion as well as 36 National Collegiate Athletic Association student-athletes without a concussion. All participants completed a multifaceted concussion baseline consisting of 1) 22-item 0-6 self-reported symptom checklist with outcomes including both the number of symptoms endorsed (0-22) and 2) total symptom score (0-132), 3) Standard Assessment of Concussion, 4) Balance Error Scoring System, 5) Immediate Post-Concussion Assessment and Cognitive Testing, 6) clinical reaction time, and 7) the King-Devick as well as demographic and injury characteristics. The concussion participants completed the same examination acutely postconcussion, and binary logistic regression was used to identify predictors of subsequent MSK from the change scores (acute minus baseline). From the 66 concussed student-athletes, a subset 36, matched with the healthy athletes, compared the risk of subsequent MSK in the year before and year after their concussion. RESULTS The concussion participants were 1.78 times (95% confidence interval, 1.12-2.84; P = 0.015) more likely to suffer a lower extremity MSK in the year after their concussion than the control participants. The participant demographics and injury characteristics (P = 0.318) and concussion clinical outcomes (P = 0.461) did not predict subsequent MSK. CONCLUSION The concussion participants were 1.78 times more likely to sustain a subsequent MSK; however, no demographic, injury characteristic, or concussion assessments predicted the MSK. Thus, clinicians are not able to utilize common neurological measures or participant demographics to identify those at risk for subsequent lower extremity MSK. Injury prevention strategies should be considered for collegiate student-athletes upon premature return to participation after a concussion to reduce the subsequent MSK.

Concussion pre-injury (i.e., baseline) assessments serve as a benchmark comparison point in the event an individual sustains a concussion and allows clinicians to compare to post-injury measures. However, baseline assessments must reflect the individual’s true and most optimized performance to serve as a useful comparison. Mental fatigue and motivation throughout baseline testing may alter individual assessment performance, indicating an order of administration (OoA) may play an influential role in assessment outcomes. To examine the influence concussion baseline battery OoA has on symptom, postural stability, cognitive screening, and computerized neurocognitive test outcomes. We employed a retrospective observational cohort study to examine healthy collegiate student-athletes and military cadets (n = 2898, 19.0 ± 1.4 years, 66.1% male, 75.6% white, 54.4% Division-I) baseline assessment performance on the Sport Concussion Assessment Tool (SCAT; total symptom number and severity), Balance Error Scoring System (BESS; total error scores), Standardized Assessment of Concussion (SAC; total score), and Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) domain scores (verbal and visual memory, visual-motor speed, reaction time). Assessments were binned to beginning, middle, or end tertiles based upon OoA. We used one-way ANOVAs with Tukey post-hoc t tests, 95% confidence intervals (CI), and Cohen’s d effect sizes for significant models (α = 0.05). SCAT total symptom number (mean difference = 2.23; 95% CI 1.76–2.70; d = 0.49, p

Primary objective: To describe and compare athletic trainer (AT) post-concussion driving management practices and opinions.Research design: Cross-sectional.Methods & procedures: A survey was sent via email to 8,723 ATs (10.8% response rate[945/8723]) to capture demographics, management practices, and opinions (agreement on a seven-point Likert scale). We used Kruskal-Wallis tests to compare the percentage of patients instructed to refrain from driving across the highest earned a degree, setting, and years certified (alpha = 0.05).Main outcomes & results: When asked whether they recommended patients with concussion refrain from driving, 58.5%(n = 553/945) of ATs responded "sometimes", 37.9%(n = 358/945) responded "always", and 3.6%(n = 34/945) responded "never". ATs responding "sometimes" or "always" estimated that they instruct 57.6 ± 37.6% of patients with concussion to refrain from driving. ATs most commonly: recommended that patients refrain from driving until symptom resolution(44.7%,n = 399/892); utilized their clinical exam (patient interview/history) to determine when a patient could resume driving(64.9%,n = 579/892); and provided instructions verbally(94.2%,n = 840/892). High school(60.5 ± 37.6%) and clinical ATs(66.5 ± 31.2%) trended toward higher percentages of patients they instruct to refrain from driving relative to college(52.3 ± 38.2%; χ2(2) = 5.92,p = .052).Conclusions: ATs recommend driving restrictions to some, but not all, patients with concussion. Overall, ATs recognize post-concussion driving dangers, but do not strongly endorse refraining from driving after a concussion. High school and clinical ATs may manage more adolescent novice drivers and, therefore, act more conservatively.

Our purpose was to describe the youth flag football head impact burden and make comparisons with youth tackle football. Head impact frequency and magnitude (linear acceleration [g], rotational acceleration [rad/s

Background: Impairments in postural stability are common following concussion. However, subjectively-scored assessments of postural control, such as the Balance Error Scoring System, may not accurately reflect postural instability. Objective measures, such as gait performance, can more accurately identify ongoing impairments in postural control throughout concussion recovery. Recent technological advances make gait evaluations more feasible across different clinical settings. Purpose: To compare performance on smartphone measured single- and dual-task gait evaluations among adolescent concussion participants and healthy controls across two timepoints. Methods: We evaluated concussed participants at initial (n=13; 14.6±1.3 years; 54% female; 5.5±1.6 days post-concussion) and follow-up visits (33.2±3.3 days post-concussion), and healthy control participants (n=21; 15.5±1.6 years; 48% female) at two timepoints 27.3±0.7 days apart on single- and dual-task gait performance. Single-task gait trials consisted of walking at a self-selected pace for 20 meters. Single-task cognitive trials involved responding to a cognitive task while standing in place. For dual-task trials, participants completed gait and cognitive tasks simultaneously. During each trial a smartphone affixed to the lumbar spine measured gait velocity and cognitive response accuracy and response time. We conducted a 2x2 mixed effects ANOVA to examine changes between groups across the testing timeline. Results: Concussion participants reported significantly greater symptom severity than control participants at the initial timepoint (23.1±13.5 vs 7.4±8.5; p=0.001); however, this difference did not persist to the second timepoint (p=0.99). The concussion group demonstrated significant improvements in single-task gait velocity between timepoints; although, between-group differences in gait velocity were not observed at either timepoint (Figure 1). No differences in cognitive accuracy between groups were identified. However, concussed participants performed worse than healthy controls on cognitive response time at both time points in single- and dual-task testing (Figure 2). Further, response time improved between testing periods for single-task, but not dual-task, conditions. Conclusion: Smartphone gait evaluations indicate improvement in single-task gait velocity during concussion recovery. However, no significant differences in gait velocity were found between concussed and control participants at either time point in single- or dual-task gait conditions. Interestingly, concussion patients had slower cognitive responses than healthy controls at both time points, despite no differences in cognitive accuracy or symptom severity at time 2. Our preliminary findings suggest that smartphone gait evaluations are effective in measuring changes in gait velocity and cognitive performance following adolescent concussion, as well as detecting subtle differences in gait and cognitive performance between concussed and control patients throughout recovery. [Figure: see text][Figure: see text]

To study sex and sport differences in baseline clinical concussion assessments. A secondary purpose was to determine if these same assessments are affected by self-reported histories of (1) concussion; (2) learning disability; (3) anxiety and/or depression; and (4) migraine.Prospective cohort.National Collegiate Athletic Association D1 Universities.Male and female soccer and lacrosse athletes (n = 237; age = 19.8 ± 1.3 years).Sport, sex, history of (1) concussion; (2) learning disability; (3) anxiety and/or depression; and (4) migraine.Sport Concussion Assessment Tool 22-item symptom checklist, Standardized Assessment of Concussion, Balance Error Scoring System (BESS), Generalized Anxiety Disorder 7-item scale, and Patient Health Questionnaire.Female athletes had significantly higher total symptoms endorsed (P = 0.02), total symptom severity (P0.001), and BESS total errors (P = 0.01) than male athletes. No other sex, sport, or sex-by-sport interactions were observed (P0.05). Previous concussion and migraine history were related to greater total symptoms endorsed (concussion: P = 0.03; migraine: P = 0.01) and total symptom severity (concussion: P = 0.04; migraine: P = 0.02). Athletes with a migraine history also self-reported higher anxiety (P = 0.004) and depression (P = 0.01) scores. No other associations between preexisting histories and clinical concussion outcomes were observed (P0.05).Our findings reinforce the need to individualize concussion assessment and management. This is highlighted by the findings involving sex differences and preexisting concussion and migraine histories.Clinicians should fully inventory athletes' personal and medical histories to better understand variability in measures, which may be used to inform return-to-participation decisions following injury.

Background/Purpose: Multiple sclerosis (MS) is a progressive neurological disease that results in increased fatigue, decreased muscle function, and impaired gait and balance. The purpose of this study was to evaluate the relationship between lower leg muscle function and changes in gait and balance immediately and 20 minutes after 6mins walk-induced fatigue. Methods: Six persons with MS (Patient-Determined Disease Steps 3-5) participated in the study. Perceived fatigue and demographic information were taken at baseline. Muscle fatigability and mitochondria capacity was measured in the lower leg muscles before walking. Reported fatigue (VAFS, 0-10), gait variability, gait asymmetry, and static balance were measured before and immediately after a self-paced 6 minutes treadmill walk with slight elevation, and after 20 minutes of rest. Results: Participant’s baseline MFIS score ranged from 14 - 71. There was a 173% increase in reported fatigue scores after walking. Gait was impaired with a ~26% increase in gait variability and ~40% increase in gait asymmetry immediately after walking (Cohen’s D = 0.4, 0.3 respectively). There was also ~69% increase in balance postural sway with eyes opened and a ~20% increase with eyes closed (Cohen’s D = 0.5, 0.2 respectively). Gait and balance remained impaired after 20 minutes of rest. The decline in gait parameters after walking had a negative correlation with muscle endurance (r=-0.80, p=0.03), and mitochondrial capacity (r=-0.92, p

Recent literature has indicated altitude may be a protective factor for concussion but it is unknown whether altitude or heat index affects recovery.To examine whether on-field heat index and altitude at the time of injury alter acute ( 48 h) concussion assessments, days-to-asymptomatic, and days-to-return-to-play in collegiate athletes following concussion.Collegiate athletes (n = 187; age = 19.7 ± 1.4 years; male = 70.6%) underwent baseline assessments across 30 universities and experienced a concussion in this retrospective cohort study. Altitude (m) and heat index (°C) at the time and location of injury were determined using valid online database tools. Acute concussion assessments included the Sport Concussion Assessment Tool (SCAT) symptom inventory, Balance Error Scoring System (BESS), and the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). We used multiple linear regression models to determine whether heat index and altitude predicted each acute assessment outcome, days-to-asymptomatic, and days-to-return-to-play.Collegiate athletes were concussed at a 181.1 m (range - 0.6 to 2201.9 m) median altitude and 17.8 °C (range - 6.1 to 35.6 °C) median heat index. Altitude did not predict (p ≥ 0.265) any outcomes. Every one-degree increase in heat index reduced days-to-asymptomatic (p = 0.047; ROur findings suggest that on-field altitude and heat index at the time of injury do not contribute to clinically meaningful changes on acute assessments or concussion recovery. On-field altitude and heat index do not appear to significantly alter assessment outcomes or clinical recovery, suggesting that environmental factors at altitudes below 2500 m are negligible outcomes for researchers and clinicians to consider post-concussion.