Effect of Concussion on Performance of National Football League Players

Int J Sports Physiol Perform. 2017 Sep;12(8):1100-1104. doi: 10.1123/ijspp.2016-0508. Epub 2017 Jan 17.


Purpose: Lingering neurologic injury after concussion may expose athletes to increased risk if return to play is premature. The authors explored whether on-field performance after concussion is a marker of lingering neurologic injury.

Design: Retrospective cohort study on 1882 skill-position players who played in the National Football League (NFL) during 2007-2010.

Methods: Players with concussion based on the weekly injury report were compared with players with other head and neck injuries (controls) on measures of on-field performance using Football Outsiders' calculation of defense-adjusted yards above replacement (DYAR), a measure of a player's contribution controlling for game context. Changes in performance, relative to a player's baseline level of performance, were estimated before and after injury using fixed-effects models.

Results: The study included 140 concussed players and 57 controls. Players with concussion performed no better or worse than their baseline on return to play. However, a decline in DYAR relative to their prior performance was noted 2 wk and 1 wk before appearing on the injury report. Concussed players performed slightly better than controls in situations where they returned to play the same week as appearing on the injury report.

Conclusions: On return, concussed NFL players performed at their baseline level of performance, suggesting that players have recovered from concussion. Decline in performance noted 2 wk and 1 wk before appearing on the injury report may suggest that concussion diagnosis was delayed or that concussion can be a multihit phenomenon. Athletic performance may be a novel tool for assessing concussion injury and recovery.

Keywords: American football; NFL; head injury.

MeSH terms

  • Athletic Performance / physiology*
  • Brain Concussion / diagnosis*
  • Football / injuries*
  • Football / physiology
  • Humans
  • Retrospective Studies
  • Return to Sport*
  • Time Factors