Purpose

Hamstring injuries are prevalent among athletes who engage in high-intensity sports requiring explosive sprints and rapid directional changes, such as soccer. These injuries can have a profound impact on player performance and return-to-play (RTP) timelines, influencing long-term career outcomes. This study aims to evaluate the effects of hamstring injuries on RTP and subsequent player performance in Major League Soccer (MLS) players over a 10-year period.

Methodology

This retrospective matched-cohort study analyzed MLS who sustained hamstring injuries between 2010 and 2021. Player performance metrics, including games played, minutes played, goals, assists, and other relevant statistics, were extracted from MLS databases. Uninjured controls were matched with injured players in a 2:1 ratio to assess the impact of hamstring injuries on post-injury performance. Statistical analyses, primarily t-tests, were used to determine significant differences in performance between the injured cohort and controls over a three-year post-injury period.

Results

In total, 1,255 MLS players with hamstring injuries were identified and compared with matched controls. Analysis revealed that forwards with hamstring injuries experienced a significant decrease in assists per season three years post-injury compared to controls (1.54 injured [I]; 3.12 uninjured [U], p=0.030). While midfielders did not show significant differences in most metrics, there was a decline in goals per season three years post-injury (1.56 [I]; 1.90 [U], p=0.231). Defenders demonstrated a significant reduction in minutes played per season two years post-injury compared to controls (1391.84 [I]; 1713.91 [U], p=0.007), indicating a substantial impact on their playing time. Although goalkeepers showed a non-significant trend towards fewer clean sheets three years post-injury, the overall decline in performance was less pronounced (1394.75 [I];1636.88 [U], p=0.273).

Conclusion

The study highlights that hamstring injuries in MLS players have varying impacts on RTP and performance based on playing position. Defenders and forwards appear to be more affected in terms of playing time and assists (-322.07 minutes; -1.58 assists), respectively, while midfielders and goalkeepers experience less pronounced performance declines (-0.34 goals; -242.13 clean sheets), respectively. These findings underscore the importance of position-specific rehabilitation and RTP protocols to optimize recovery and long-term performance outcomes for players with hamstring injuries.