Objective To determine whether reaction time or postural stability measures obtained after concussion return-to-play clearance are predictive of a sport-related injury in the subsequent year.

Design Prospective cohort study.

Setting Single-institution primary care sports medicine center.

Assessment of Risk Factors Participants completed a test battery following return-to-play clearance post-concussion, and subsequently completed monthly injury/exposure logs over the subsequent year.

Outcome Measures Participants completed four tests: simple reaction time (response to green dot turning red), clinical reaction time (grasping a stick with hockey puck attached; calculating drop distance), single/dual-task tandem gait (heel-toe walking along a path 3m down-back), and modified Balance Error Scoring System (mBESS; eyes closed on firm ground). Participants completed monthly injury logs over the subsequent year documenting injury exposure/incidence.

Main Results Thirty-six adolescents completed the test battery and monthly injury logs (50% female; age=15.4±1.6 years). Twenty (56%) reported a sport-related injury. After adjusting for age, slower simple reaction time was associated with a higher hazard of injury over the post-concussion year (hazard ratio=1.007, 95% CI=1.001–1.014; p=0.024). Clinical reaction time (hazard ratio=0.97, 95% CI=0.95–1.01; p=0.08), single-task tandem gait (hazard ratio=0.99, 95% CI=0.89–1.10; p=0.88), dual-task tandem gait (hazard ratio=1.03, 95% CI=0.95–1.11; p=0.53), and BESS errors (hazard ratio=0.97, 95% CI=0.78–1.20; p=0.78) were not significantly associated with hazard of injury.

Conclusions A clinically feasible simple reaction time measure provided utility in identifying individuals with increased risk of sustaining an injury after return-to-play clearance post-concussion. Clinicians may consider screening tools that include reaction time to facilitate safe return-to-play in adolescents after concussion.

Trial Registration NCT03917290