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.

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.

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.

Repetitive head impacts do not affect postural control following a competitive athletic season.

Evidence suggests that Repetitive Head Impacts (RHI) directly influence the brain over the course of a single contact collision season yet do not significantly impact a player's performance on the standard clinical concussion assessment battery. The purpose of this study was to investigate changes in static postural control after a season of RHI in Division I football athletes using more sensitive measures of postural control as compared to a non-head contact sports. Fourteen Division I football players (CON) (age=20.4±1.12years) and fourteen non-contact athletes (NON) (2 male, 11 female; age=19.85±1.21years) completed a single trial of two minutes of eyes open quiet upright stance on a force platform (1000Hz) prior to athletic participation (PRE) and at the end of the athletic season (POST). All CON athletes wore helmets outfitted with Head Impact Telemetry (HIT) sensors and total number of RHI and linear accelerations forces of each RHI were recorded. Center of pressure root mean square (RMS), peak excursion velocity (PEV), and sample entropy (SampEn) in the anteroposterior (AP) and mediolateral (ML) directions were calculated. CON group experienced 649.5±496.8 mean number of impacts, 27.1±3.0 mean linear accelerations, with ≈1% of total player impacts exceeded 98g over the course of the season. There were no significant interactions for group x time RMS in the AP (p=0.434) and ML (p=0.114) directions, PEV in the AP (p=0.262) and ML (p=0.977) directions, and SampEn in the AP (p=0.499) and ML (p=0.984) directions. In addition, no significant interactions for group were observed for RMS in the AP (p=0.105) and ML (p=0.272) directions, PEV in the AP (p=0.081) and ML (p=0.143) directions, and SampEn in the AP (p=0.583) and ML (p=0.129) directions. These results suggest that over the course of a single competitive season, RHI do not negatively impact postural control even when measured with sensitive non-linear metrics.

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.

ASB clinical biomechanics award winner 2016: Assessment of gaze stability within 24-48hours post-concussion.

BACKGROUND: Approximately 90% of athletes with concussion experience a certain degree of visual system dysfunction immediately post-concussion. Of these abnormalities, gaze stability deficits are denoted as among the most common. Little research quantitatively explores these variables post-concussion. As such, the purpose of this study was to investigate and compare gaze stability between a control group of healthy non-injured athletes and a group of athletes with concussions 24-48hours post-injury. METHODS: Ten collegiate NCAA Division I athletes with concussions and ten healthy control collegiate athletes completed two trials of a sport-like antisaccade postural control task, the Wii Fit Soccer Heading Game. During play all participants were instructed to minimize gaze deviations away from a central fixed area. Athletes with concussions were assessed within 24-48 post-concussion while healthy control data were collected during pre-season athletic screening. Raw ocular point of gaze coordinates were tracked with a monocular eye tracking device (240Hz) and motion capture during the postural task to determine the instantaneous gaze coordinates. This data was exported and analyzed using a custom algorithm. Independent t-tests analyzed gaze resultant distance, prosaccade errors, mean vertical velocity, and mean horizontal velocity. FINDINGS: Athletes with concussions had significantly greater gaze resultant distance (p=0.006), prosaccade errors (p<0.001), and horizontal velocity (p=0.029) when compared to healthy controls. INTERPRETATION: These data suggest that athletes with concussions had less control of gaze during play of the Wii Fit Soccer Heading Game. This could indicate a gaze stability deficit via potentially reduced cortical inhibition that is present within 24-48hours post-concussion.

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.

Scapular Upward-Rotation Deficits After Acute Fatigue in Tennis Players.

CONTEXT: Fatigue in overhead athletes reduces shoulder muscular contraction and proprioception. These deficits may lead to alterations in scapular upward rotation, which is associated with multiple chronic shoulder conditions prevalent in tennis players. OBJECTIVE: To identify the effect of a functional fatigue protocol on scapular upward rotation in collegiate male tennis players. DESIGN: Randomized controlled clinical trial. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty healthy male tennis players with no history of shoulder injury completed this study. Participants were divided into 2 groups, experimental (age = 19.4 ± 1.1 years, height = 180.1 ± 8.9 cm, weight = 72.7 ± 11.6 kg) and control (age = 19.6 ± 1.2 years, height = 181.1 ± 6.6 cm, weight = 81.6 ± 13.5 kg). INTERVENTION(S): Participants in the experimental group performed a tennis-serving protocol until the onset of fatigue. Fatigue was defined as a participant reporting a rating of 15 on the Borg Scale of Perceived Exertion and reaching a heart rate of 70% of maximum. Instead of completing the fatigue protocol, control participants rested for an interval time matched to the experimental group. MAIN OUTCOME MEASURE(S): Scapular upward rotation of the dominant arm was measured at rest and at 60°, 90°, and 120° of glenohumeral elevation in the scapular plane. Upward-rotation measurements were taken prefatigue, postfatigue, and at 24, 48, and 72 hours postexercise. Scapular upward-rotation values were calculated as change scores from baseline and analyzed using a 2 × 4 mixed-model analysis of variance. RESULTS: Significant group-by-time interaction effects were found in postfatigue change scores. The experimental group displayed scapular upward-rotation deficits at all testing positions postfatigue (rest: -2.1° ± 1.4°, 60°: -2.2° ± 2.2°, 90°: -3.2° ± 2.1°, 120°: -4.0° ± 1.3°). No differences were observed at 24, 48, or 72 hours after the fatigue protocol. CONCLUSIONS: Fatigue impaired scapular upward rotation in male tennis players, but values returned to baseline within 24 hours. Clinicians should monitor scapular upward rotation in tennis players returning to competition within a day after heavy serving activity.

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.

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.

Sideline Performance of the Balance Error Scoring System during a Live Sporting Event.

OBJECTIVE: The purpose was to examine the influence of a live sporting sideline environment on balance error scoring system (BESS) performance. DESIGN: Prospective longitudinal cohort study. SETTING: The BESS was performed by all participants at 3 locations: (1) quiet laboratory, (2) football stadium sidelines, and (3) basketball arena sidelines. PARTICIPANTS: The experimental group had 38 participants (age: 20.1 ± 1.1 years; height: 170.0 ± 7.7 cm; mass: 66.7 ± 9.5 kg) who were female intercollegiate student-athletes (SA). The control group consisted of 38 recreationally active female college students (age: 20.8 ± 1.1 years; height: 162.6 ± 6.0 cm; mass: 63.7 ± 10.6 kg). INTERVENTIONS: The 2 groups performed the tests at the same locations, the SA group during live sporting events and the control group when no event was occurring. MAIN OUTCOME MEASURES: The dependent variable was the total BESS score. Separate 2 × 3 mixed methods analyses of variance investigated the influence of the environment and practice effect. RESULTS: There was a significant interaction for group by environment (P = 0.004), and the SA group committed more errors at both the football and the basketball settings than the control group. The SA group also committed more errors at football (P = 0.028) than baseline. The control group demonstrated a likely practice effect with fewer errors during each administration. CONCLUSIONS: The BESS score deteriorated when performed on the sidelines of a live sporting event potentially challenging the clinical utility of the BESS. Clinicians need to consider the role of the local environment when performing the BESS test and should perform postinjury tests in the same environment as the baseline test. CLINICAL RELEVANCE: When performing balance testing of patients with suspected concussions, clinicians need to consider the environment in which the test is performed and attempt to match the preseason testing environment.

Balance error scoring system performance changes after a competitive athletic season.

OBJECTIVE: To evaluate the change in Balance Error Scoring System (BESS) performance after an athletic season. DESIGN: A prospective longitudinal group study. SETTING: University biomechanics research laboratory. PARTICIPANTS: A total of 58 college-aged females (23 soccer student-athletes, 16 volleyball student-athletes, and 19 recreationally active healthy college students) participated in the study. INTERVENTIONS: The BESS test was administered on 2 occasions 90 days apart. For the student-athletes, the first test (PRE) was administered before the start of their athletic season and the second test (POST) was administered immediately after the season. For the recreationally active college students, the PRE test was at the beginning of the academic semester and the POST test exactly 90 days thereafter. MAIN OUTCOME MEASURES: Total BESS score at PRE and POST was compared with a 3 × 2 repeated measures analysis of variance. The overall change score and absolute value change score were also calculated and compared with a 1-sample t test to an expected change of zero errors. RESULTS: There was no group by time interaction; however, there was a main effect for time. There was a significant improvement (P = 0.003) between PRE (9.00 ± 2.97 errors) and POST (7.92 ± 2.78 errors) BESS performance. There were significant differences for both the overall change score (1.08 errors) and the absolute value change score (2.00 errors). CONCLUSIONS: A clinically and statistically significant difference in BESS performance was identified after a 90-day intercollegiate athletic season.

Altered gait termination strategies following a concussion.

The purpose was to determine if planned gait termination can identify acute and lingering motor control strategy alterations in post-concussion individuals. Controls completed two standard gait and five planned gait termination trials once while concussed individuals were tested on Day-1 and Day-10 post-concussion. Dependent variables included gait velocity and normalized, relative to standard gait, peak propulsive and braking forces. Control and only Day-1 post-concussion gait velocity differed. Normalized peak propulsive and braking forces were altered on both Day-1 and Day-10. Altered propulsive and braking forces persisted despite all concussion participants achieving their baseline values on standard concussion clinical tests. Thus gait termination can detect both acute and lingering motor control strategy alterations following concussion.

Comparison of split double and triple twists in pair figure skating.

In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.

Comparison of Cervical Spine Motion During Application Among 4 Rigid Immobilization Collars.

OBJECTIVE: To quantify the cervical spine range of motion that occurred during application of 4 rigid cervical immobilization collars, the time of application, and the amount of active range of motion available after application. DESIGN AND SETTING: We evaluated the amount of cervical motion that occurred during application of 4 commonly used collars: NECLOC (NL), StifNeck (SN), StifNeck Select (SNS), and Rapid Form Vacuum Immobilizer (VI). Each clinician applied a properly sized collar to both a small- and medium-size model 3 times. After application, active range-of-motion testing was completed with the subject in the supine and seated positions. SUBJECTS: A total of 17 certified athletic trainers participated. MEASUREMENTS: We used 3-dimensional kinematic head and thorax data to calculate peak angular displacement, total linear distance, and total angular distance during application and peak angular displacement during supine and seated range-of-motion testing. Application time was calculated during each trial. RESULTS: Significant differences between collars were noted for application time, total linear distance, and total angular distance (P<.01). The SN and SNS were applied significantly faster and with significantly less total linear distance and total angular distance than the NL and the VI collars. The NL was applied significantly faster and with significantly less total linear distance and total angular distance than the VI. During supine and seated active range-of-motion tests, the SN and SNS permitted significantly less cervical flexion-extension, rotation, and lateral flexion than the NL and VI. CONCLUSIONS: Of the collars tested, the SN and SNS appear to be the optimal collars for use by certified athletic trainers. They were applied with the least motion in the fastest time and provided superior restriction during active range-of-motion testing.