Concussion and National Hockey League Player Performance: An Advanced Hockey Metrics Analysis

Abstract

Context: Postconcussion deficits in neurocognitive performance and postural control may persist at the time of return to sport participation. How these deficits, if present, affect athletic performance is largely unknown, with prior studies showing mixed results.Objective: To evaluate postconcussion National Hockey League player performance using advanced hockey metrics over short-(5 games), medium-(10 games), and long-term (remainder of the season) seasonal performance.Design: Retrospective cohort study. Patients or Other Participants: National Hockey League players who sustained a sport-related concussion (SRC; n ¼ 93) and returned during the same season and players (n ¼ 51) who missed time for non-injury-related reasons.Main Outcome Measure(s): Six performance metrics were used: (1) points per 60 minutes, (2) Corsi percentage, (3) personal Fenwick shooting percentage, (4) scoring chances per 60 minutes, (5) penalty difference, and (6) PDO (not an acronym but sometimes referred to as SVSP% [save percentage shooting percentage]). Performance was compared using 2 (group) 3 2 (time) repeated-measures analyses of variance for 3 time windows: (1) 65 games, (2) 610 games, and (3) the remainder of the season postconcussion. Alpha values were set at a conservative .01 to account for the lack of independence among dependent variables.Results: No significant interactions were present for any of the 6 dependent variables at any of the 3 time windows. Overall, none of the secondary variables differed.Conclusions: Using advanced, sport-specific metrics, we found that National Hockey League players did not display worse seasonal performance during 3 postinjury time frames after they sustained an SRC. Whereas laboratory studies have identified lingering neurologic deficits after concussion, our results suggest that these deficits, if present, either do not translate to worse athletic performance or were not captured by these 44 metrics. Further, prospective efforts are needed to accurately quantify performance after SRC among professional hockey players.

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

“…When compared with matched controls, players after a concussion demonstrated no statistically significant difference in short- and long-term performance. The maintained short-term performance revealed in our study corroborated the findings of Buckley et al, 3 who conducted a case series on the performance on 93 NHL players after concussion. The authors reported no difference in points per 60 minutes, Corsi percentage, Fenwick percentage, penalty difference, or PDO at 5 games, at 10 games, or for the remainder of the index season after concussion.…”

Performance After Concussion in National Hockey League Players

“…Their primary outcomes and performance indicators were similar to ours. Buckley et al 7 investigated the same cohort of injuries but used advanced hockey metrics in an attempt to detect more subtle metrics of player decline after injury; they included an expanded postinjury time frame (5 games, 10 games, and the remainder of the season) to detect more long-term effects of SRC. However, they also noted no deficits at any of the 3 time points after the return from injury.…”

“…However, they also noted no deficits at any of the 3 time points after the return from injury. Buckley et al 7 explored a control group of players who missed time for noninjury reasons and determined that their postconcussion performance was similar to that of the control participants. Our results support the evidence from previous researchers that players did not experience performance deficits when returning to the NHL after an SRC.…”

“…From 2008 to 2015, NHL players who returned from SRC showed no differences in performance or style of play, as measured via standard statistics (eg, goals and assists), compared with uninjured players. 6 Recently, researchers 7 who used advanced analytical statistics that detect more subtle performance changes found no change in player performance after returning from SRC.…”

Participation in pre-injury level sport one-year following sport-related concussion: A prospective, matched cohort study

“…4,5 However, upon returnto-play some professional athletes have temporarily impaired sporting performance (e.g., adjusted plus-minus National Hockey League [NHL] scores and lower batting averages and decreased on-base percentages in Major League Baseball [MLB]) up to six weeks after sport-related concussion. 6,7 Many factors (e.g., psychological responses, medical care, and social support) [8][9][10] may influence athletes' time taken to return to their pre-injury level of sport competition, and then their sustained participation at pre-injury levels of sport competition after they have returned, following sport-related concussion. As such, it is important for many athletes who have sustained a sport-related concussion, and for their healthcare providers, to set a goal of returning to the same competitive level of sport to which the athlete was participating prior to injury.…”