Change in Head Impact Exposure following Return-to-Sport in Concussed Football Athletes.

Purpose: Following sport-related concussions, early head impact exposure and premature return-to-sport are known to increase risk of repeat concussion in football athletes, yet athletes' true post-injury head impact exposure profiles (i.e., characteristics of recorded head impacts over a given time period) and biomechanical progression have not been explored. Accordingly, this study explored how head impact exposure in American college football athletes was altered during their return to sport from concussion, particularly within the same athletic season.

Methods: This analysis compared daily volume of head impacts following concussion with pre-injury levels using head impact exposure profiles of fifty-two concussed collegiate football athletes from six NCAA Division I programs, and further compared these athletes to team- and position-matched controls to minimize season- or team-related factors. Additionally, this study provided an analysis of the possible association between duration of recovery and change in head impact exposure following concussion using continuous linear regression.

Results: When comparing to pre-injury levels, 75% of concussed athletes reduced their head impact exposure in their immediate return-to-sport, while over 40% of concussed athletes did not reach their pre-injury level of head impact exposure at any point during the remainder of the concussion season segment. Furthermore, concussed athletes significantly decreased their head impact exposure over their immediate return-to-sport period when compared to team- and position-matched healthy, non-concussed athletes over the same time period. Finally, longer post-concussion recovery times were associated with larger decreases in head impact exposure after return-to-sport.

Conclusions: This study provides evidence for a shift in head impact exposure after returning from concussion, seen most strongly in the immediate days after return-to-sport. These findings align with the recent shift toward more conservative post-concussion management seen across multiple sports and playing levels.