Increased Auditory Dual Task Cost During Gait Initiation in Adult Patients With Persistent Concussion Symptoms.

OBJECTIVE: To compare dual task cost (DTC) during gait initiation (GI) between a population of patients with persistent concussion symptoms (PCS) and age-matched healthy participants. DESIGN: Cohort study. SETTING: University research center. PARTICIPANTS: A cohort sample including 15 participants with PCS (43.9±11.7y, 73.3% female) and 23 age-matched healthy participants (42.1±10.3y, 65.2% female) as controls. INTERVENTIONS: Participants were tested on a single occasion where they performed 5 trials of single task and 5 trials of dual task GI with 12-camera motion capture and 3 force plates. MAIN OUTCOME MEASURES: The dependent variables of interest were the DTC for the center of pressure (COP) displacement and velocity during the anticipatory postural adjustment (APA) phase, the COP-center of mass (COP-COM) separation, and the response accuracy during the auditory cognitive tasks. RESULTS: There were significant group differences with worse DTC for the PCS participants in anterior (A)/posterior (P) displacement (PCS, -37.5±22.1%; Control, -9.7±39.2%; P=.016, d=0.874), APA medial (M)/lateral (L) velocity (PCS, -34.8±28.8%; Control, -17.0±40.21%; P=.041, d=0.866), and the peak COP-COM separation (PCS, -7.3±6.7%; Control, 0.6±6.5%; P=.023, d=1.200). There were no significant group differences in the APA A/P velocity (PCS, -38.8±33.1%; Control, -19.8±43.9%; P=.094), APA M/L displacement (PCS, -34.8±21.8%; Control, -10.6±25.3%; P=.313), or cognitive task performance (PCS, -2.7±10.8%; Control, -0.2±4.3%; P=.321). CONCLUSIONS: PCS participants had greater (worse) DTC during both the planning and execution of the task, with large effect sizes (d>0.80). PCS participants also used a posture-second strategy whereby attentional resources were inappropriately allocated to the cognitive task. These deficits may challenge a patient's ability to complete activities of daily living and limit their functional independence.

Collegiate student-athletes concussion knowledge and attitudes: what a difference a decade Makes.

OBJECTIVE: The purpose of this study was to assess changes in concussion knowledge and attitudes amongst incoming intercollegiate student-athletes over the course of a decade (2010-2012 vs 2021-2023). METHODS: There were 592 student-athletes from 2 cohorts (2010-2012, 2021-2023) who completed the Rosenbaum Concussion Knowledge and Attitudes Survey (ROCKaS) questionnaire which is comprised of a concussion knowledge index (CKI, 0-24) and attitude index (CAI, 15-75) with higher scores reflecting better performance. A three factor ANOVA (Group, Sex, Concussion History) compared performance on the CKI and CAI. Individual questions were compared between groups with a Chi-Square analysis. RESULTS: For the CKI, there was a significant main effect for Group (2010-2012: 18.5 ± 2.6, 2021-2023: 19.4 ± 2.5, p < 0.001, η2=0.032). For the CAI, there was also a significant main effect for group (2010-2012: 52.9 ± 6.0, 2021-2023: 62.2 ± 6.5, p < 0.001, η2=0.359). CONCLUSIONS: The results of this study show a modest increase in concussion knowledge; however, large improvements in concussion attitudes were observed between groups. These results suggest a continued improvement in student-athlete concussion awareness and provide specific areas to continue addressing persistent misconceptions.

Projected Changes in Statin and Antihypertensive Therapy Eligibility With the AHA PREVENT Cardiovascular Risk Equations.

Importance: Since 2013, the American College of Cardiology (ACC) and American Heart Association (AHA) have recommended the pooled cohort equations (PCEs) for estimating the 10-year risk of atherosclerotic cardiovascular disease (ASCVD). An AHA scientific advisory group recently developed the Predicting Risk of cardiovascular disease EVENTs (PREVENT) equations, which incorporated kidney measures, removed race as an input, and improved calibration in contemporary populations. PREVENT is known to produce ASCVD risk predictions that are lower than those produced by the PCEs, but the potential clinical implications have not been quantified. Objective: To estimate the number of US adults who would experience changes in risk categorization, treatment eligibility, or clinical outcomes when applying PREVENT equations to existing ACC and AHA guidelines. Design, Setting, and Participants: Nationally representative cross-sectional sample of 7765 US adults aged 30 to 79 years who participated in the National Health and Nutrition Examination Surveys of 2011 to March 2020, which had response rates ranging from 47% to 70%. Main Outcomes and Measures: Differences in predicted 10-year ASCVD risk, ACC and AHA risk categorization, eligibility for statin or antihypertensive therapy, and projected occurrences of myocardial infarction or stroke. Results: In a nationally representative sample of 7765 US adults aged 30 to 79 years (median age, 53 years; 51.3% women), it was estimated that using PREVENT equations would reclassify approximately half of US adults to lower ACC and AHA risk categories (53.0% [95% CI, 51.2%-54.8%]) and very few US adults to higher risk categories (0.41% [95% CI, 0.25%-0.62%]). The number of US adults receiving or recommended for preventive treatment would decrease by an estimated 14.3 million (95% CI, 12.6 million-15.9 million) for statin therapy and 2.62 million (95% CI, 2.02 million-3.21 million) for antihypertensive therapy. The study estimated that, over 10 years, these decreases in treatment eligibility could result in 107 000 additional occurrences of myocardial infarction or stroke. Eligibility changes would affect twice as many men as women and a greater proportion of Black adults than White adults. Conclusion and Relevance: By assigning lower ASCVD risk predictions, application of the PREVENT equations to existing treatment thresholds could reduce eligibility for statin and antihypertensive therapy among 15.8 million US adults.

Test-Retest Reliability and Efficacy of Individual Symptoms in Concussion Management.

OBJECTIVE: (1) To determine test-retest reliability of individual Sport Concussion Assessment Tool-Third Edition (SCAT-3) symptom scores and symptom severity scores, (2) to examine the specificity/sensitivity of individual SCAT-3 symptom severity scores acutely (24-48 hours) postconcussion, and (3) to develop a model of symptoms best able to differentiate concussed from nonconcussed student athletes and cadets. DESIGN: Prospective, longitudinal, and cross-sectional. SETTING: Twenty-six civilian schools and 3 US service academies. PARTICIPANTS: Collegiate student athletes (n = 5519) and cadets (n = 5359) from the National Collegiate Athletic Association-Department of Defense Grand Alliance: Concussion Assessment, Research and Education Consortium, including 290 student athletes and 205 cadets, assessed 24 to 48 hours postconcussion. INDEPENDENT VARIABLES: Concussed and nonconcussed student athlete and cadet groups. MAIN OUTCOME MEASURES: Sport Concussion Assessment Tool-Third Edition individual symptom severity scores, total symptom scores, and symptom severity scores. RESULTS: Results indicated poor test-retest reliability across all symptom scores (intraclass correlation coefficient = 0.029-0.331), but several individual symptoms had excellent predictive capability in discriminating concussed from nonconcussed participants (eg, headache, pressure in the head, and don't feel right had area under the curve >0.8, sensitivity >70%, and specificity >85%) regardless of baseline testing. These symptoms were consistent with Chi-square Automatic Interaction Detector classification trees with the highest mean probability. CONCLUSIONS: Findings support the excellent diagnostic accuracy of honest symptom reporting, notwithstanding the known limitations in symptom underreporting, and suggest that there may be added value in examining individual symptoms rather than total symptom scores and symptom severity scores alone. Finally, findings suggest that baseline testing is not necessary for interpreting postconcussion symptom scores.

Quantitative Analysis of Ball-Head Impact Exposure in Youth Soccer Players.

Since the implementation of the US Soccer heading guidelines released in 2015, little to no research on ball-head impact exposure in the United States youth soccer population has been conducted. The purpose was to compare ball-head impact exposure across sex and age in youth soccer players over a weekend tournament. Ten male and female games for each age group (Under-12 [U12], U13, and U14) were video recorded at a weekend tournament for a total of 60 games. Ball-head impact exposure for each game was then coded following a review of each recording. Male players were 2.8 times more likely to have ball-head impacts than female players, (p < 0.001) particularly in the U14 age group when compared to the U12 age group (p = 0.012). Overall 92.4% of players experienced 0-1 ball-head impacts per game with the remaining players experiencing 2+ ball-head impacts per game. Ball-head impact exposure levels are low in the youth players. Most youth soccer players do not head the soccer ball during match play and those that did, only headed the ball on average once per game. Overall, the difference in ball-head impact exposure per player was less than 1 between all the groups, which may have no clinical meaning.

Single-Task and Dual-Task Tandem Gait Performance Across Clinical Concussion Milestones in Collegiate Student-Athletes.

OBJECTIVE: To determine the length of time after concussion that impaired tandem gait performance is observed. DESIGN: Clinical measurement, prospective longitudinal. SETTING: NCAA collegiate athletic facility. PARTICIPANTS: Eighty-eight concussed NCAA Division I student-athletes and 30 healthy controls. INDEPENDENT VARIABLES: Group (concussion/control) and time (Baseline, Acute, Asymptomatic, and RTP). MAIN OUTCOME MEASURES: Participants completed 4 single-task and dual-task tandem gait trials. The concussion group completed tests at the following time points: preseason (Baseline), within 48 hours after concussion (Acute), on the day symptoms were no longer reported (Asymptomatic), and when cleared to return to sports (RTP). Controls completed the same protocol at similar intervals. The dual-task trials involved minimental style cognitive questions answered simultaneously during tandem gait. We analyzed the best time of the 4 trials, comparing groups with a linear mixed model. RESULTS: Acutely after concussion, the concussion group performed single-task tandem gait slower (worse) than controls (concussion: 11.36 ± 2.43 seconds, controls: 9.07 ± 1.78 seconds, P < 0.001). The concussion group remained significantly slower than controls (9.95 ± 2.21 vs 8.89 ± 1.65 seconds, P = 0.03) at Asymptomatic day but not RTP. There were significant group (P < 0.001) and time (P < 0.001) effects for dual-task tandem gait. The groups were not significantly different at baseline for single-task (P = 0.95) or dual-task (P = 0.22) tandem gait. CONCLUSIONS: Our results indicate that tandem gait performance is significantly impaired acutely after concussion, compared with both preseason measures and controls. Postural control impairments were not present when the student-athletes were cleared for RTP. This information can assist clinicians when assessing postural control and determining recovery after a concussive injury.

Postural Control Deficits After Repetitive Soccer Heading.

OBJECTIVE: To determine the acute effects of repetitive soccer heading on postural control. DESIGN: Prospective study; participants were divided into 2 groups: a soccer heading group and a control group. SETTING: Biomechanics laboratory. PARTICIPANTS: One hundred sixty participants, including youth (age = 13.0 ± 0.8 years), high school (age = 17.2 ± 1.0 years), and collegiate (age = 20.2 ± 1.3 years) male and female soccer players, participated in this study. INTERVENTIONS: Participants in the soccer heading group performed 12 soccer headers (initial velocity = 11.2 m/s). Postural control testing was performed both before (PRE) and immediately after (POST) the purposeful soccer headers. Control participants performed postural control testing PRE and POST a 15-minute wait period. During postural control testing, participants were asked to stand on the MobileMat (Tekscan Inc, Boston, Massachusetts) for two 2-minute intervals with their hands on their hips and their feet together with one eyes-open and one eyes-closed trial. MAIN OUTCOME MEASURES: Using the center-of-pressure data, 95% area, sway velocity, and ApEn were calculated. Multilevel linear models were used to analyze the effects of age, sex, group, condition, and concussion history simultaneously. RESULTS: Participants in the soccer heading group had significantly higher sway velocity POST than participants in the control group after controlling for age, sex, concussion history, condition, and PRE (t = -3.002; P = 0.003; 95% confidence interval, -0.482 to -0.100). There were no significant differences from PRE to POST for 95% area, M/L ApEn, and A/P ApEn. CONCLUSIONS: Repetitive soccer heading does not affect most postural control measures, even among youth athletes. However, sway velocity increased after heading relative to control participants independent of age, sex, and concussion history.

Differential Effects of Acute and Multiple Concussions on Gait Initiation Performance.

OBJECTIVE: To identify the effect of acute and multiple concussions on gait initiation performance. DESIGN: Cohort study. SETTING: University research center. PARTICIPANTS: A population-based sample of participants (N=45) divided into 3 groups: No Prior Concussion, ≥3 Prior Concussions, and Acute Concussion. The Acute Concussion participants were assessed within 24 hours of their concussion. Participants were matched based on (1) sport, (2) position, and (3) anthropometric measures. INTERVENTIONS: Participants were tested on a single occasion and performed 5 trials of gait initiation on 4 force plates. The No Prior Concussion and ≥3 Prior Concussions groups were tested out of their primary athletic season. MAIN OUTCOME MEASURES: The dependent variables were the posterior and lateral displacement and velocity of the center of pressure (COP) during the anticipatory postural adjustment phase and initial step kinematics (step length and step velocity). Comparisons between groups used a 1-way analysis of variance with Tukey post hoc when significant effects were identified and effect sizes were calculated. RESULTS: There were significant effects for group for all 6 outcome measures with large effect sizes. Post hoc tests identified differences between Acute Concussion and No Prior Concussion groups for all measures. The ≥3 Prior Concussions group and No Prior Concussion group were different for COP posterior displacement (4.91±1.09 and 4.91±1.09cm, respectively, P=.032, d=0.91) and velocity (0.18±0.06 and 0.27±0.08m/s, respectively, P=.002, d=1.27). CONCLUSION: There was continuum of performance identified whereby the Acute Concussion participants performed worse and the No Prior Concussion participants performed the best. The ≥3 Prior Concussions generally fell between these 2 groups, but only statistical significance on COP posterior displacement and velocity. These results suggest there may be subtle neurophysiological deficits present in collegiate student-athletes with ≥3 Prior Concussions group, and further investigation over the lifespan is warranted.

King-Devick Test Time Varies by Testing Modality.

OBJECTIVE: To explore differences in baseline King-Devick Test (KD) completion time between 2 testing modalities: (1) spiral-bound paper cards (cards) and (2) iPad application (iPad). DESIGN: Cross-sectional cohort analysis. SETTING: National Collegiate Athlete Association (NCAA) institutions. PARTICIPANTS: Student athletes from 13 women's and 11 men's collegiate sports who completed KD baseline testing as part of their first year in the Concussion Assessment, Research and Education (CARE) Consortium from 2014 to 2016 (n = 2003, 52.2% male). INDEPENDENT VARIABLES: King-Devick Test modalities; cards or iPad. MAIN OUTCOME MEASURE: Baseline KD completion time (seconds). RESULTS: Mean baseline KD completion time of the iPad modality group [42.8 seconds, 95% confidence interval (CI), 42.1-43.3] was 2.8 seconds (95% CI, 2.1-3.4) greater than the cards group (40.0 seconds, 95% CI, 39.7-40.3) (t(1, 1010.7) = -8.0, P < 0.001, Cohen's d = 0.41). CONCLUSIONS: Baseline KD performance is slower when tested on an iPad than when tested on spiral-bound paper cards. The 2 KD modalities should not be used interchangeably in concussion assessments because differences in the modalities can lead to time differences similar in magnitude to those used to indicate concussion. From a research perspective, modality may influence interpretation and/or synthesis of findings across studies.

Turn Characteristics During Gait Differ With and Without a Cognitive Demand Among College Athletes.

CONTEXT: Sports often involve complex movement patterns, such as turning. Although cognitive load effects on gait patterns are well known, little is known on how it affects biomechanics of turning gait among athletes. Such information could help evaluate how concussion affects turning gait required for daily living and sports. OBJECTIVE: To determine the effect of a dual task on biomechanics of turning while walking among college athletes. DESIGN: Cross-sectional study. SETTING: University laboratory. PARTICIPANTS: Fifty-three participants performed 5 trials of a 20-m walk under single- and dual-task conditions at self-selected speed with a 180° turn at 10-m mark. The cognitive load included subtraction, spelling words backward, or reciting the months backward. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Turn duration, turning velocity, number of steps, SD of turn duration and velocity, and coefficient of variation of turn duration and velocity. RESULTS: Participants turned significantly slower (155.99 [3.71] cm/s vs 183.52 [4.17] cm/s; P < .001) and took longer time to complete the turn (2.63 [0.05] s vs 2.33 [0.04] s; P < .001) while dual tasking, albeit taking similar number of steps to complete the turn. Participants also showed more variability in turning time under the dual-task condition (SD of turn duration = 0.39 vs 0.31 s; P = .004). CONCLUSIONS: Overall, college athletes turned slower and showed more variability during turning gait while performing a concurrent cognitive dual-task turning compared with single-task turning. The slower velocity increased variability may be representative of specific strategy of turning gait while dual tasking, which may be a result of the split attention to perform the cognitive task. The current study provides descriptive values of absolute and variability turning gait parameters for sports medicine personnel to use while they perform their concussion assessments on their college athletes.

Does baseline concussion testing aid in identifying future concussion risk?

The purpose was to determine differences in pre-season baseline performance between student-athletes who suffered a future sport-related concussion (fSRC) and those who did not. Collegiate student-athletes (82 fSRC, 82 matched control, age = 18.4 ± 0.8years, height = 172.7 ± 10.3 cm, mass = 80.1 ± 20.9 kg) completed baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Balance Error Scoring System (BESS), and Standardized Assessment of Concussion (SAC). Results of the independent t-tests suggested there were no differences between the fSRC and the control groups for ImPACT composite scores (95% confidence intervals, Visual Memory: fSRC 70.4-75.9, Control 73.4-78.5, p = 0.134; Verbal Memory: fSRC 83.8-87.7, Control 85.7-89.9, p = 0.155; Reaction Time: fSRC 0.562-0.591, Control 0.580-0.614, p = 0.071; Visual Motor Speed: fSRC 38.5-41.1, Control 38.2-40.9, p = 0.757), BESS total errors (fSRC 11.3-13.7, Control 11.8-14.4, p = 0.483), or SAC (fSRC 26.6-27.4, Control 26.9-27.6, p = 0.394). Receiver operating characteristic (ROC) areas-under-the-curve were 0.417-0.515. Our findings suggest that baseline concussion assessments cannot be used to predict individuals who may sustain a fSRC.

Dual-Task Tandem Gait and Average Walking Speed in Healthy Collegiate Athletes.

OBJECTIVES: To (1) examine the association between a commonly used concussion test, tandem gait, in single/dual-task conditions with single-task and dual-task average walking speed, (2) characterize the prevalence of tandem gait false positives, and (3) develop a normative reference range of dual-task tandem gait times. DESIGN: Cross-sectional study. SETTING: Two NCAA collegiate athletic facilities. INDEPENDENT VARIABLES: Athletes completed the tandem gait test and a gait evaluation in single/dual-task conditions during a preseason examination. MAIN OUTCOME MEASURES: Associations between tandem gait times and average walking speeds were evaluated using multiple linear regression models. Various tandem gait test time pass/fail cutoffs were calculated to examine false-positive rates. RESULTS: Among the 171 participants (103 men, 19.8 ± 1.2 years of age), dual-task tandem gait completion times were independently associated with dual-task average walking speed [ß = -4.018; 95% confidence interval (CI), -7.153 to -0.883], but single-task associations were not found. Male gender was associated with faster tandem gait times in both single-task (ß = -0.880, 95% CI, -1.731 to -0.029) and dual-task conditions (ß = -2.225, 95% CI, -3.691 to -0.759). A pass/fail cutoff threshold of 14 seconds resulted in a 2% false-positive rate for single-task tandem gait, while it resulted in a 29% false-positive rate during dual-task tandem gait. CONCLUSIONS: Average walking speed and dual-task tandem gait represent objective measures that are useful in concussion management. While a single-task tandem gait cutoff of 14 seconds seems appropriate for males, adjustments may be necessary based on sex and alternate pass/fail criteria may be appropriate for dual-task tandem gait.

Identification of Post-Concussion Dual-Task Gait Abnormalities Using Normative Reference Values.

Our purpose was to identify the rate of abnormal single-task and dual-task gait performance acutely post-concussion relative to uninjured controls using previously established normative reference values. We examined athletes with a concussion (n=54; mean age=20.3±1.1 years of age, 46% female, tested 2.9±1.5 days post-injury) and healthy controls tested during their preseason baseline examination (n=60; 18.9±0.7 years of age, 37% female). Participants completed an instrumented single/dual-task gait evaluation. Outcome variables included average walking speed, cadence, and step length. A significantly greater number of those with concussion walked with abnormal dual-task gait speed compared to the control group (56% vs. 30%; p= 0.008). After adjusting for potential confounding variables (age, concussion history, symptom severity, and sleep), concussion was associated with lower dual-task gait speed (ß=-0.150; 95% CI=-0.252,-0.047), cadence (ß= -8.179; 95% CI=-14.49,-1.871), and stride length (ß=-0.109; 95% CI=-0.204,-0.014). Although group analyses indicated that those with a concussion performed worse on single-task and dual-task gait compared to controls, a higher rate of abnormal gait was detected for the concussion group compared to the control group for dual-task gait speed only. Dual-task gait speed, therefore, may be considered as a measure to compare against normative values to detect post-concussion impairments.

Sensitivity and Specificity of the Modified Balance Error Scoring System in Concussed Collegiate Student Athletes.

OBJECTIVE: To assess the efficacy of the modified Balance Error Scoring System (mBESS) compared with the Balance Error Scoring System (BESS) in an acutely concussed population. DESIGN: Prospective observational study. SETTING: University athletic training room. PATIENTS: Thirty-five collegiate student-athletes (18 Female, 18.9 ± 0.8 year old, height: 1.71 ± 0.12 m, weight: 76.3 ± 24.1 kg) with diagnosed concussions and baseline BESS/mBESS tests. INTERVENTIONS: All participants completed the BESS and mBESS on the day after the concussion (acute) and were retested daily until their BESS score achieved baseline value (recovery). MAIN OUTCOME MEASURES: The number of errors committed during the BESS and mBESS at each time point were recorded. The sensitivity and specificity of the BESS and mBESS compared with the baseline test was calculated for acute and recovery as well as the mBESS compared with the BESS. RESULTS: At acute, the sensitivity of the BESS and mBESS were 60.0% and 71.4%, respectively. Relative to mBESS baseline, 60% of participants were misclassified at either acute or recovery. CONCLUSIONS: The mBESS had higher sensitivity at acute and identified lingering deficits at BESS recovery. Use of the mBESS is likely to produce different results than the BESS; however, the clinical implications of this warrant further investigation.

Sex and age differences in head acceleration during purposeful soccer heading.

Differences in head-neck segment mass, purposeful heading technique, and cervical strength and stiffness may contribute to differences in head accelerations across sex and age. The purpose of this study was to compare head acceleration across sex and age (youth [12-14 years old], high school and collegiate) during purposeful soccer heading. One-hundred soccer players (42 male, 58 female, 17.1 ± 3.5 years, 168.5 ± 20.3 cm, 61.5 ± 13.7 kg) completed 12 controlled soccer headers at an initial ball velocity of 11.2 m/s. Linear and rotational accelerations were measured using a triaxial accelerometer and gyroscope and were transformed to the head centre-of-mass. A MANOVA revealed a significant multivariate main effect for sex (Pillai's Trace = .165, F(2,91) = 11.868, p < .001), but not for age (Pillai's Trace = .033, F(4,182) = 0.646, p = .630). Peak linear and rotational accelerations were higher in females (40.9 ± 13.3 g; 3279 ± 1065 rad/s2) than males (27.6 ± 8.5 g, 2219 ± 823 rad/s2). These data suggest that under controlled soccer heading conditions, females may be exposed to higher head accelerations than males.

Decreased Anticipatory Postural Adjustments During Gait Initiation Acutely Postconcussion.

OBJECTIVE: To investigate anticipatory postural adjustments (APAs) during the transitional movement task of gait initiation (GI) in individuals acutely after a concussion. DESIGN: Cohort study. SETTING: University research center. PARTICIPANTS: A population-based sample of participants (N=84) divided into 2 equal groups of acutely postconcussion and healthy student athletes. INTERVENTION: Participants were tested on 2 occasions: a preinjury baseline test and then the concussion group was retested acutely postconcussion and the healthy student athlete group again at a similar time. All participants completed 5 trials of GI on 4 forceplates. MAIN OUTCOME MEASURES: The dependent variables were the displacement and velocity of the center of pressure (COP) during the APA phase and initial step kinematics. Comparisons were made with a 2 (group) × 2 (time) repeated-measures analysis of variance. RESULTS: There was a significant interaction for COP posterior displacement (P<.001) and lateral displacement (P<.001). Posteriorly, post hoc testing identified a significant reduction in the concussion group (pretest: 5.7±1.6cm; posttest: 2.6±2.1cm; P<.001), but no difference in the healthy student athlete group (pretest: 4.0±1.6cm; posttest: 4.0±2.5cm; P=.921). Laterally, post hoc testing identified a significant reduction in the concussion group (pretest: 5.8±2.1cm; posttest: 3.8±1.8cm; P<.001), but no difference in the healthy student athlete group (pretest: 5.0±2.5cm; posttest: 5.2±2.4cm; P=.485). CONCLUSIONS: The results of this study suggest difficulty in the planning and execution of GI acutely postconcussion, and posterior APA displacement and velocity are highly effective measures of impaired postural control. Finally, the APA phase is linked to the supplementary motor area, which suggests a supraspinal contribution to postconcussion impaired postural control.

Single-Task and Dual-Task Gait Among Collegiate Athletes of Different Sport Classifications: Implications for Concussion Management.

Gait impairments have been documented following sport-related concussion. Whether preexisting gait pattern differences exist among athletes who participate in different sport classifications, however, remains unclear. Dual-task gait examinations probe the simultaneous performance of everyday tasks (ie, walking and thinking), and can quantify gait performance using inertial sensors. The purpose of this study was to compare the single-task and dual-task gait performance of collision/contact and noncontact athletes. A group of collegiate athletes (n = 265) were tested before their season at 3 institutions (mean age= 19.1 ± 1.1 years). All participants stood still (single-task standing) and walked while simultaneously completing a cognitive test (dual-task gait), and completed walking trials without the cognitive test (single-task gait). Spatial-temporal gait parameters were compared between collision/contact and noncontact athletes using MANCOVAs; cognitive task performance was compared using ANCOVAs. No significant single-task or dual-task gait differences were found between collision/contact and noncontact athletes. Noncontact athletes demonstrated higher cognitive task accuracy during single-task standing (P = .001) and dual-task gait conditions (P = .02) than collision/contact athletes. These data demonstrate the utility of a dual-task gait assessment outside of a laboratory and suggest that preinjury cognitive task performance during dual-tasks may differ between athletes of different sport classifications.

Acute Cognitive and Physical Rest May Not Improve Concussion Recovery Time.

OBJECTIVE: To evaluate the effectiveness of an acute period of cognitive and physical rest on concussion. PARTICIPANTS: Fifty consecutive patients with a diagnosis of concussions. DESIGN: Participants were evaluated before (n = 25) and after (n = 25) a policy change that incorporated cognitive and physical rest. Patients in the rest group were withheld from activities, including classes, for the remainder of the injury day and the following day, whereas patients in the no-rest group were not provided any postinjury accommodations. MAIN MEASURES: Patients were evaluated on a graded symptom checklist, Balance Error Scoring System, Standard Assessment of Concussion, and computerized neuropsychological tests. The number of days until each test achieved baseline values was compared between groups with independent-samples t test. RESULTS: The no-rest group achieved asymptomatic status sooner than the rest group (5.2 ± 2.9 days and 3.9 ± 1.9 days, respectively; P = .047). There were no differences between groups for time to baseline values on the Balance Error Scoring System, Standard Assessment of Concussion, computerized neuropsychological tests, or time to clinical recovery. CONCLUSION: A prescribed day of cognitive and physical rest was not effective in reducing postconcussion recovery time. These results agree with a previous study and suggest that light activity postconcussion may not be deleterious to the concussion recovery process.

Predictors of postconcussion syndrome in collegiate student-athletes.

OBJECTIVE Sport-related concussion (SRC) has emerged as a public health problem, especially among student-athletes. Whereas most concussions resolve by 2 weeks, a minority of patients experience postconcussion syndrome (PCS), in which symptoms persist for months. The objective of this study was to elucidate factors predictive of PCS among a sample of National Collegiate Athletic Association (NCAA) student-athletes in the academic years 2009-2010 to 2014-2015. METHODS The SRC data originated from the NCAA Injury Surveillance Program (ISP) in the 2009-2010 to 2014-2015 academic seasons. The NCAA ISP is a prospective database made up of a convenience sample of schools across all divisions. All SRCs are reported by certified athletic trainers. The PCS group consisted of concussed student-athletes with concussion-related symptoms that lasted ≥ 4 weeks. The non-PCS group consisted of concussed student-athletes with symptom resolution in ≤ 2 weeks. Those with symptoms that resolved in the intermediate area of 2-4 weeks were excluded. Odds ratios (ORs) were estimated using logistic regression. RESULTS During the 2009-2010 to 2014-2015 seasons, 1507 NCAA student-athletes sustained an SRC, 112 (7.4%) of whom developed PCS (i.e., concussion-related symptoms that lasted ≥ 4 weeks). Men's ice hockey contributed the largest proportion of concussions to the PCS group (28.6%), whereas men's football contributed the largest proportion of concussions in the non-PCS group (38.6%). In multivariate analysis, recurrent concussion was associated with increased odds of PCS (OR 2.08, 95% CI 1.28-3.36). Concussion symptoms that were also associated with increased odds of PCS included retrograde amnesia (OR 2.75, 95% CI 1.34-5.64), difficulty concentrating (OR 2.35, 95% CI 1.23-4.50), sensitivity to light (OR 1.97, 95% CI 1.09-3.57), and insomnia (OR 2.19, 95% CI 1.30-3.68). Contact level, sex, and loss of consciousness were not associated with PCS. CONCLUSIONS Postconcussion syndrome represents one of the most impactful sequelae of SRC. In this study of exclusively collegiate student-athletes, the authors found that recurrent concussions and various concussion-related symptoms were associated with PCS. The identification of initial risk factors for the development of PCS may assist sports medicine clinicians in providing timely interventions and treatments to prevent morbidity and shorten recovery time after SRC.

Sway Area and Velocity Correlated With MobileMat Balance Error Scoring System (BESS) Scores.

The Balance Error Scoring System (BESS) is often used for sport-related concussion balance assessment. However, moderate intratester and intertester reliability may cause low initial sensitivity, suggesting that a more objective balance assessment method is needed. The MobileMat BESS was designed for objective BESS scoring, but the outcome measures must be validated with reliable balance measures. Thus, the purpose of this investigation was to compare MobileMat BESS scores to linear and nonlinear measures of balance. Eighty-eight healthy collegiate student-athletes (age: 20.0 ± 1.4 y, height: 177.7 ± 10.7 cm, mass: 74.8 ± 13.7 kg) completed the MobileMat BESS. MobileMat BESS scores were compared with 95% area, sway velocity, approximate entropy, and sample entropy. MobileMat BESS scores were significantly correlated with 95% area for single-leg (r = .332) and tandem firm (r = .474), and double-leg foam (r = .660); and with sway velocity for single-leg (r = .406) and tandem firm (r = .601), and double-leg (r = .575) and single-leg foam (r = .434). MobileMat BESS scores were not correlated with approximate or sample entropy. MobileMat BESS scores were low to moderately correlated with linear measures, suggesting the ability to identify changes in the center of mass-center of pressure relationship, but not higher-order processing associated with nonlinear measures. These results suggest that the MobileMat BESS may be a clinically-useful tool that provides objective linear balance measures.