Acute Lower Extremity Injury Rates Increase after Concussion in College Athletes

Dynamic postural control deficits and disrupted cortical pathways have been reported to persist beyond an athlete's return to activity after concussion, potentially increasing the risk of acute lower extremity musculoskeletal injury. Purpose: This study aimed to investigate acute lower extremity musculoskeletal injury rates before and after concussion in athletes with concussion and their matched control. Methods: College athletes with concussion (n = 44; age, 20.0 ± 1.2 yr) were physician-diagnosed. Nonconcussed college athletes (n = 58; age, 20.5 ± 1.3 yr) were matched to individuals with concussion. Acute lower extremity musculoskeletal injury data were collected for 2 yr (±1 yr of the diagnosed concussion) using electronic medical records. Control participants' 2-yr window for exposure and musculoskeletal injury data were anchored to their match's concussion injury date. Pre- and postconcussion musculoskeletal injury rates were calculated for 90-, 180-, and 365-d periods for both study cohorts. Risk ratios were calculated to determine differences within and between groups for all periods. Results: Within 1 yr after concussion, the group with concussion was 1.97 (95% confidence interval (CI), 1.19-3.28; P = 0.01) times more likely to have experienced an acute lower extremity musculoskeletal injury after concussion than before concussion and 1.64 times (95% CI, 1.07-2.51; P = 0.02) more likely to have experienced an acute lower extremity musculoskeletal injury after concussion than their matched nonconcussed cohort over the same period. Up to 180 d after concussion, the group with concussion was 2.02 (95% CI, 1.08-3.78; P = 0.02) times more likely to have experienced an acute lower extremity musculoskeletal injury after concussion than before concussion. Conclusions: Previous literature has identified dynamic postural control deficits along with increased motor evoked potential latency and decreased amplitude after concussion, suggesting that the brain may be unable to effectively coordinate movement. Our findings underscore the need to explore functional movement and dynamic postural control assessments in postconcussion injury assessment protocols.