The impact of concussion on subsequent injury risk in elite junior Australian football athletes

Objectives: Concussion increases injury risk. However, this has not been investigated in junior Australian football and it is unknown whether the location, severity, and mechanism of subsequent injuries differ after concussion vs. non-concussion injury. Design: Prospective cohort. Methods: 1455 elite adolescent male Australian footballers were tracked across seven seasons to determine whether subsequent injury risk was greater after concussion compared to non-concussion index injury using multilevel survival analysis. Mixed-effects logistic regression compared location and mechanism. Mixed-effects Poisson regression compared severity. Results: Of 1455 athletes, 632 were injured and included in subsequent-injury analysis. There were no differences in injury incidence after a concussion compared to upper- (hazard ratio = 1.0, 0.6 to 1.9, P = 0.892; trivial effect) and lower (hazard ratio = 1.1, 0.6 to 1.9, P = 0.810; trivial effect) index injury, or in location. Subsequent injuries were more likely to be contact-based after a non-concussion injury than concussion (odds ratio = 4.6, 1.3 to 16.0; P = 0.017; large effect). There was no difference in subsequent injury severity after lower- (3.4 & PLUSMN; 3.0 missed matches; incidence rate ratio = 1.4, 0.9 to 2.1; P & LE; 0.117; small effect) and upper-limb injuries (3.4 & PLUSMN; 3.1 missed matches; incidence rate ratio =1.4, 0.9 to 2.2; P = 0.189; small effect) compared to concussion (2.4 & PLUSMN; 2.0 missed matches). Conclusions: Subsequent injury risk, severity, and location in junior Australian football are similar following concussion compared to non-concussion index injuries, although contact injuries are less likely. & COPY; 2023 The Author(s). Published by Elsevier Ltd on behalf of Sports Medicine Australia. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).