Barry A. Munkasy

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.

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.

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.

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.

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.

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.

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 players 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.

ASB clinical biomechanics award winner 2016: Assessment of gaze stability within 24–48 hours 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 24–48 hours 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 (240 Hz) 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 24–48 hours post‐concussion. HighlightsGaze stability was assessed immediately post‐concussion during a antisaccade task.Raw ocular point of gaze coordinates were tracked with an eye tracking device.Prosaccade errors and mean horizontal velocity were significantly elevated.Data suggests potential gaze stability deficits immediately post‐concussion.Results could indicate reduced cortical inhibition post‐concussion.