An Absence of Persistent Postural Stability Deficits Following a Sport Concussion in Collegiate Athletes

Abstract

Objective: The purpose of our study was to determine whether persistent postural stability deficits exist in athletes following sport concussion (SC) in comparison with preinjury (baseline) values using Sample Entropy (SampEn). Setting: Sports medicine clinic. Patients or Other Participants: Participants consisted of 71 collegiate athletes (44 male, 27 female) with an average age of 19.9 ± 0.96 years who had a history of 1 concussion that occurred during their time as a collegiate athlete. Design: In our prospective, cohort design participants completed the Sensory Organization Test (SOT) at baseline, upon reporting symptom-free following a diagnosed SC, and upon establishing a new baseline prior to the start of the subsequent sport season. Main Outcome Measures: The SOT's condition scores were calculated and analyzed in alignment with the manufacturer's instructions. SampEn was calculated in the anterior-posterior (AP) and medial-lateral (ML) directions from the center-of-pressure oscillations over the 20-second time series for each SOT condition. The SOT and SampEn outcome scores for each condition were analyzed with repeated-measures analyses of variance. Results: Significant main effects were observed for the SOT's conditions 3 (F 1.6, 114.8 = 7.83, P = .001, η 2 = 0.10 [0.02-0.20]), 5 (F 1.8, 126.8 = 11.53, P < .001, η 2 = 0.14 [0.04-0.25]), and 6 (F 1.9, 134.5 = 25.11, P < .001, η 2 = 0.26 [0.14-0.37]), with significant improvements across time. Significant main effects were also observed for SampEn in the AP direction for conditions 3 (F 2, 140 = 7.59, P = .001, η 2 = 0.10 [0.02-0.19]) and 6 (F 2, 140 = 6.22, P = .003, η 2 = 0.08 [0.011-0.170]), with significant improvements across time. Conclusions: Following a diagnosed SC, our results suggest that collegiate athletes returned if not exceeded baseline values at the symptom-free and new baseline assessments. The application of linear and nonlinear measures of postural stability following a SC yielded similar outcomes in conjunction with a baseline assessment. Our findings support the clinical utility of the baseline SC assessment when evaluating persisting balance deficits when using linear or nonlinear measures.