Objective: After concussion, athletes have an increased risk of subsequent injuries upon return to play (RTP) compared with nonconcussed peers. Cervical spine, vestibular, and oculomotor deficits have been observed after concussion, but associations with subsequent injuries have not been established. Our objective was to investigate whether head repositioning accuracy (HRA) and vestibular/oculomotor symptoms were associated with postconcussion injuries. Design: Prospective cohort. Setting: Academic research laboratory. Participants: Adolescent athletes ages 13 to 18 years after concussion. Independent Variables: HRA error, vestibular/oculomotor symptoms. Main Outcome Measures: We evaluated athletes at RTP clearance and monitored injury incidence for 1 year through monthly surveys. At RTP, we assessed HRA (outcome: mean HRA error across 12 trials) and the visiovestibular examination (VVE; outcome: number of subtests that provoked symptoms) to assess vestibular/oculomotor symptoms. We used Cox proportional hazards regression models to assess hazard of subsequent injury, adjusting for RTP clearance time and prior concussion/musculoskeletal injury. Results: Forty-five participants were included (age = 15.8 ± 1.3 years, 58% female). Nineteen athletes reported 24 injuries during the 1-year follow-up. After adjusting for RTP clearance and prior concussion/musculoskeletal injury, greater HRA error was associated with higher hazard of subsequent injury (hazard ratio HR: 1.46; 95% confidence interval CI, 1.03-2.08; P = 0.03); VVE symptom provocation was not (HR: 0.87; 95% CI, 0.64-1.19; P = 0.39). Conclusions: Worse HRA may be associated with higher hazard of postconcussion injury. HRA is a clinically feasible assessment that may identify some individuals with increased injury risk who may benefit from further evaluation/rehabilitation before RTP.
Smulligan et al. (Wed,) studied this question.