Concussion in American Versus European Professional Soccer: A Decade-Long Comparative Analysis of Incidence, Return to Play, Performance, and Longevity

Abstract

Background: The incidence and effect of sports-related concussions (SRCs) within the global sport of professional soccer is poorly described. Purpose: To comparatively examine the effects of SRC on athletes in Major League Soccer (MLS) and the English Premier League (EPL) in terms of incidence, return to play (RTP), performance, and career longevity. Study Design: Cohort study; Level of evidence, 3. Methods: Contracts, transactions, injury reports, and performance statistics from 2008 to 2017 were obtained and cross-referenced across 6 publicly available websites detailing MLS and EPL data, including official league publications. For each league, players who sustained a concussion were compared with the 2008-2017 uninjured player pool. RTP and games missed were analyzed and compared. Career length was analyzed with Kaplan-Meier survival curves. Player performance changes were evaluated before and after concussion. Results: Of the 1784 eligible MLS and 2001 eligible EPL players evaluated over the 10-year period, the incidence of publicly reported concussions per 1000 athlete-exposures was 20.22 and 18.68, respectively ( P = .53). The incidence of reported concussions steadily increased in both leagues. MLS players missed a mean 7.3 games after concussion (37.0 days missed); EPL players missed a mean 0.6 games after concussion (10.9 days missed) ( P < .0001, P < .0001). Statistical performance in terms of games started, assists, shots on goal, and total shots after concussion was significantly reduced at all nongoalie positions for players in the EPL; however, MLS nongoalie positions with concussion had no significant decreases in these categories. Goalies in both leagues had no significant change in performance or games started. The probability of playing a full season after concussion was not significantly decreased when compared with the uninjured pool in both leagues. Conclusion: This study established the SRC incidence among elite soccer players in 2 international professional leagues and identified major RTP and performance differences between EPL and MLS players. While career longevity was unaffected, the approach to managing concussion as in MLS may better promote player safety and preserve on-field performance.

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

“…23 However, the proportion of professional English Premier League (EPL), Major League Soccer (MLS), and MLB players participating in respective English and North American sports leagues one-year after sport-related concussion was not significantly different compared with non-concussed players. 7,24 The similarity of the current study's findings with the findings of studies of professional collision sport athletes (NFL & NHL), 21,22 rather than contact sport athletes (EPL, MLS, & MLB), 7,24 one-year following sport-related concussion may be explained by the proportion of collision sport athletes in our study sample and the rate of athlete attrition in collision sports that is due to injury.…”

Observable player behaviours and playing performance following helmet strikes in elite cricket

“…A possible explanation for this may be the management of RTP following concussion. In elite soccer, Ramkumar et al 7 demonstrated that players returning through more aggressive protocols suffered a decrement in performance versus those managed more conservatively.…”

“…However, there is also the potential for impaired playing performance, increased musculoskeletal injury risk and, in elite sport, limitation of career length and earning potential in the short-and medium-term following concussion. [3][4][5][6][7] There are also concerns around repetitive 'sub-concussive' impacts and the potential for these accumulated impacts to be as important in the short-and long-term brain health of athletes. [8][9][10] Improved understanding of head impact injuries in cricket is important, particularly given approximately 70% of concussions occurring after such injuries are not diagnosed at the time of the strike.…”

Heads-Up: Risk-Specific Neurodegenerative Mortality and Years-Saved Analysis on the US Olympian Cohort

“…In the Contact category, sports with less frequent and often not purposeful shock on the head (e.g., basketball, soccer, and gymnastics) were included ( Table 1 ; Reynolds et al, 2017 ). The remaining sports were classified under the No-Contact category (e.g., athletics, archery, and swimming) ( Ramkumar et al, 2019 ).…”