Concussions in the National Hockey League: Analysis of Incidence, Return to Play, and Performance

BACKGROUND: Concussion injuries are common in professional hockey; however, their effect on player performance remains unclear. PURPOSE: To quantify the effect of concussions on the performance of position players in the National Hockey League (NHL). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Concussion data from the NHL were collected using publicly available databases for the seasons between 2009-2010 and 2015-2016, coinciding with new NHL concussion rules. Age, body mass index, position, number of concussions during a player's NHL career, games played, and time on ice were recorded. Basic and advanced performance metrics were collected for 1 season pre- and postconcussion (short-term period) and 3 seasons before and after concussion (long-term period) to assess short- and long-term changes in performance. A control group of players without an identified concussion who competed during the study period was assembled for comparison. Wilcoxon signed rank tests were used to evaluate pre- to postconcussion data in the short- and long-term settings as well as to compare the cohorts at each time point. CONCLUSION: A high rate of NHL players were able to return to play after a concussion injury. Players with concussion did not experience a reduction in performance metrics in the short- or long-term setting when compared with matched controls. The concussed cohort maintained a similar workload up to 3 seasons postconcussion but played in fewer career games when compared with matched controls.