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.

Stop the Bleed®: Medical Students as Instructors of the Bleeding Control Basics Course.

BACKGROUND: The Bleeding Control Basics (B-Con) Course was developed to teach lifesaving hemorrhage control techniques to the public. Currently, medical students (MS) without prior clinical experience (CE) may not act as autonomous instructors, limiting the instructor pool. PURPOSE: To assess the bleeding control knowledge of MS (phase I) and compare the knowledge of students taught by a certified instructor vs a medical student (phase II). METHODS: Phase I: 20 MS, 6 with prior CE and 14 without clinical experience (NCE) completed a pre-course and post-course knowledge assessment. Results were assessed by independent sample t-tests. Phase II: 91 first-year MS were taught the B-Con Course by either a third-year MS (n = 45) or certified instructor (n = 46). An analysis of covariance (ANCOVA) was performed to compare scores by instructor type (certified vs MS) using prior CE and pretest scores as confounding variables. RESULTS: In Phase I, the CE group scored higher on the pretest assessment compared to the NCE group (P = .003). All students improved in posttest scoring, and there was no difference in posttest scores between the groups (P = .597). In Phase II, despite no difference in pretest scores between groups, the MS taught learners scored significantly higher on the posttest compared to the certified instructor group (P < .01). Prior CE did not correlate to posttest scores (P = .719). DISCUSSION: Medical students are as effective as certified instructors at conveying the B-Con learning objectives. Based on near-perfect assimilation of content by students, MS should be permitted to teach B-Con Courses.

Acute Physical and Mental Activity Influence on Concussion Recovery.

INTRODUCTION: Physical activity (PA) and mental activity (MA) postconcussion has received renewed attention to improve concussion management; however, most protocols start after several days and do not assess the acute window. Therefore, the purpose of this study was to assess PA and MA in the first 48 h postconcussion on the time to symptom-free status and return to play. METHODS: We recruited 78 NCAA Division I athletes (male, 51.3%; age, 19.6 ± 1.4 yr; height, 173.7 ± 11.5 cm; weight, 80.1 ± 23.2 kg) who were diagnosed with a sports-related concussion. Participants completed a 0-5 PA and MA scale daily until fully cleared for return to participation (mean, 15.1 ± 6.9 d). A quadratic model regression assessed PA and MA over the first 2 d (acute) postconcussion on to time to symptom-free status and return to play. RESULTS: The overall model was significant for both time to symptom free (r2 = 0.27, P = 0.004) and return to play (r2 = 0.23, P = 0.019). Reported PA was the only significant predictor for time to symptom-free (P = 0.002) and return-to-participation (P = 0.006) day. Reported MA was not associated either outcome. CONCLUSIONS: The primary finding of this study was that mild to moderate PA acutely postconcussion was associated with reduced time to symptom free and return to participation as opposed to either lower or higher levels of PA. Conversely, acute MA was not associated with recovery outcomes. These results further elucidate the role of postconcussion PA.

Impairments in Dynamic Postural Control across Concussion Clinical Milestones.

The aim of this study was to assess gait initiation (GI) performance longitudinally across clinical concussion recovery milestones through return to participation (RTP). We recruited 54 collegiate student-athletes, 27 with concussions and 27 matched controls (15 female and 12 male per group). Participants performed five trials of GI at baseline and again at five post-concussion clinical milestones: 1) Acute, the day clinical tests achieved baseline values on the 2) Balance Error Scoring System (BESS), 3) Immediate Post-Concussion Assessment and Cognitive Test ImPACT, 4) Asymptomatic, and 5) RTP Day. GI performance on six outcome measures (anterior/posterior and medial/lateral center of pressure displacements and velocities during the anticipatory postural adjustment [APA] phase and initial step length and velocity) with repeated-measures mixed model and pair-wise post hoc. A reliable change index (RCI) was calculated, and post-concussion participant's performance was compared to the RCI at milestones. There were significant interactions for APA posterior and lateral displacement, APA posterior velocity, step length, and step velocity. The post-hoc tests identified significant deficits across clinical milestones and at RTP for APA posterior and lateral displacement, step length, and step velocity. There were no post-hoc differences for any outcome measure in the control group. At RTP, 85.2-88.9% of concussion participants had at least one outcome measure which exceeded the 80% or 95% RCI. The primary finding of this study was persistent impairments in dynamic postural control, suggesting ongoing neurophysiological impairment despite clinical recovery. These results suggest that collegiate student-athletes may be RTP before neurophysiological recovery and potentially exposing themselves to elevated risk of recurrent concussion or subsequent musculoskeletal injury.

The use of a visual motor test to identify lingering deficits in concussed collegiate athletes.

BACKGROUND: Emerging evidence suggests neurophysiological deficits, such as visual motor coordination (VMC), may persist beyond clinical concussion recovery. Instrumented measurement of upper-limb VMC is critical for neurological evaluation post-concussion and may identify persistent deficits further elucidating persistent neurophysiological impairments not detected by the current clinical assessment battery. AIM: The aim of the study was to determine if a VMC test identifies persistent deficits in concussed collegiate student-athletes who have returned to baseline on clinical concussion assessments. METHODS: Thirteen recently concussed intercollegiate student-athletes (male: 7, 18.9±0.7 years, 175.5±12.4 cm, 75.5±23.2 kg), and 13 matched control student-athletes (male: 7, 19.3±1.1 years, 173.5±11.9 cm, 75.8±19.9 kg) completed two testing sessions (T1: <48 h after clinical recovery; T2: 30 days post-concussion) on a visual motor exam. The outcome measures were A* Average score (average number of lights hit on A* exam), simple visual reaction time (SVRT)-RT, and movement time (SVRT-MT) on the Dynavision D2. The dependent variables were compared with a 2 (group) × 2 (time) repeated measures ANOVAs. RESULTS: There was no group interaction in A* average score (F(1,24)=0.036, P=0.849), SVRT-RT (F(1,22)=0.319, P=0.575), and SVRT-MT (F(1,22)=1.179, P=0.188). There was a main effect for time on A* average score (T1: 76.3±10.4 hits; T2: 82.7±11.2 hits; F(1,24)=38.1, P≤0.001) and SVRT-RT (T1: 0.31±0.04; T2: 0.29±0.04 s; F(1,22)=4.9, P=0.039). There was no main effect for SVRT-MT. There were no group differences at either time point. CONCLUSIONS: Among recently concussed collegiate student-athletes, no persistent deficits were identified in VMC beyond clinical recovery when assessed by Dynavision D2. This VMC exam may not provide a useful means of tracking recovery following concussion likely due to a substantial practice effect. RELEVANCE FOR PATIENTS: While post-concussion neurophysiological deficits persist beyond clinical recovery, the laboratory based VMC assessment herein did not identify deficits at critical post-concussion time points. Therefore, other clinically translatable VMC assessments should be further investigated.

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.

Repetitive Head Impacts in Football Do Not Impair Dynamic Postural Control.

PURPOSE: The purpose of this study was to assess the effect of repetitive head impacts experienced by football players compared to noncontact athletes on dynamic postural control during both single-task (ST) and dual-task (DT) conditions. METHODS: Thirty-four football players wearing accelerometer instrumented helmets and 13 cheerleaders performed a dynamic postural control battery, consisting of ST and DT gait initiation, gait, and gait termination, both prior to and following the football season. A 2 (group) × 2 (time) repeated measures ANOVA compared performance across 32 dynamic postural outcomes. A linear regression was performed on postural control change scores with common head impact kinematics serving as the independent variables. RESULTS: The football players experienced a mean of 538.1 ± 409.1 head impacts in the season with a mean linear acceleration of 27.8g ± 3.2g. There were no significant interactions for any of the ST or DT dynamic postural control tasks. There was a significant relationship between head impact kinematics and the lateral center of pressure displacement during the anticipatory postural adjustment phase (r = 0.26, P = 0.010) and transitional phase (r = 0.511, P = 0.042) during ST gait initiation. For both measures, the number of impacts exceeding 98g was the only significant predictor of decreased center of pressure displacement. CONCLUSIONS: A single competitive football season did not adversely affect dynamic postural control when comparing football players to cheerleaders who do not experience repetitive head impacts. Furthermore, there were limited relationships with head impact kinematics suggesting that a single season of football does not adversely affect most outcome measures of instrumented dynamic postural control. These findings are consistent with most studies which fail to identify clinical differences related to repetitive head impacts.

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.

Altered dynamic postural control during gait termination following concussion.

Impaired postural control is a cardinal symptom following concussion. Planned gait termination (GT) is a non-novel, dynamic task that challenges postural control in individuals with neurological deficits, and it could be an impactful measure for identifying dynamic postural control impairments following concussion. Therefore, the purpose of this study was to assess acute post-concussion dynamic postural control utilizing a planned GT task. The concussion participants (n=19, age: 19.0±0.8years, height: 177.0±10.1cm, weight: 83.3±20.0kg) completed five planned GT trials during preseason baseline testing (Baseline) and on Day 1 post-concussion (Day-1). Healthy control participants (n=19, age: 20.4±1.2years, height: 173.8±8.9cm, weight: 80.2±17.6kg) completed the same trials a week apart. The dependent variables of interest included COP displacement and velocity in the mediolateral (ML) and anteroposterior (AP) axes during the three phases (braking, transitional, stabilization) of planned GT. There were significant interactions observed in both the braking ML and transitional AP displacement (p=0.042, p=0.030) and velocity (p=0.027, p=0.030). These results suggest a conservative post-concussion motor control strategy during planned GT. Further, these results support the use of dynamic postural control tasks as measures of post-concussion impairments.

Evidence of a conservative gait strategy in athletes with a history of concussions.

BACKGROUND: A history of 3 or more concussions is frequently associated with numerous short- and long-term neuropathologies. Impairments in postural control are a known acute consequence of concussion; however, limited evidence exists on the effects of multiple concussions on gait. The purpose of this study was to assess gait stepping characteristics in collegiate aged student-athletes based on concussion history. METHODS: There were 63 participants divided into 3 even groups based on concussion history: ≥3 concussions, 1-2 concussions, and 0 concussion. All participants completed 10 trials of gait on a 4.9 m instrumented walkway. The dependent variables of interest included both gait stepping characteristics (step velocity, length, and width, double support time, and the percentage of the gait cycle in stance) and coefficient of variability (CoV) measures (step length, time, and width). The gait stepping characteristics were compared first with a MANOVA with follow-up 1-way ANOVAs and Tukey post hoc tests as appropriate. The CoV measures were compared with 1-way ANOVAs and Tukey post hoc tests. RESULTS: There were main effects for group for step velocity, length, width, and double support time. Overall, the 0 concussion group displayed typical healthy young gait parameters and performed significantly better than either concussion group. The 0 concussion group had a significantly greater step length CoV, but there were no differences in the step time or width CoV. CONCLUSION: This finding provides evidence of subtle impairments in postural control during gait among individuals with prior history of concussion which could be an early indicator of future neurological deficiencies. The limited difference in the variability measures is consistent with prior static stance studies and could suggest the individuals constrain their motor systems to reduce variability. Taken together, these findings suggest a conservative gait strategy which is adopted by individuals with a history of concussions.