Early Targeted Heart Rate Aerobic Exercise Reduces Proportion of Subacute Musculoskeletal Injuries After Recovery From Sport-Related Concussion

Objective: There is greater risk of musculoskeletal (MSK) injury after clinical recovery from sport-related concussion (SRC). We determined whether aerobic exercise treatment within 10 days of SRC reduced the proportion of MSK injury in recovered adolescent athletes at 4 months since injury. Design: Planned secondary analysis of a randomized trial of aerobic exercise versus stretching exercise in adolescents after SRC. Setting: Outpatient and hospital-based sports medicine centers. Participants: Aerobic exercise (n = 38, 58% male, 15.6 years) and stretching exercise (n = 25, 64% male, 15.9 years) participants completed a questionnaire at 3.5 and 3.3 months since recovery, respectively. Interventions: Individualized subthreshold aerobic exercise versus placebo-like stretching. Main Outcome Measures: Proportion of MSK injury, subsequent concussion, and return to exercise training, school, and sport determined 3 months after clinical recovery from SRC. Results: Overall, 24% of participants randomized to stretching experienced an MSK injury versus 5.3% of participants randomized to aerobic exercise. There was no difference in time to return to school, sport, or incidence of subsequent concussion. Stretching participants were 6.4 times (95% confidence interval 1.135-36.053) more likely to sustain MSK injury than aerobic exercise participants when controlling for the duration of exposure to sport and return to preinjury sport participation. All injuries were in male participants. Conclusion: Adolescent male athletes prescribed aerobic exercise within 10 days of SRC had a significantly lower proportion of individuals injured in the 3 months following clinical recovery when compared with stretching. This may be due to a habituation/rehabilitation effect of aerobic activities to improve autonomic, vestibular, and/or oculomotor function after SRC.