Poster 228: Hamstring Muscle Injuries in Major League Soccer: An Analysis of Injury Rate, Associated Factors, and Return to Play

Objectives: To examine (1) the rate and time to return play (RTP) after hamstring muscle injury, (2) investigate of reinjury RTP, (3) conditions that are associated with increased severity injury or RTP. Methods: MLS Injury Surveillance database was queried for all athletes injuries from 2010-2021 were included categorized by severity. A defined as an incident required medical attention involved biceps femoris, semimembranosus, semitendinosus. Demographic characteristics (setting activity during onset, severity, management, RTS, re-injury) collected used descriptive analysis. Results: total 2865 recorded between 2010 2021, 1227 individual players. The average injured player age 26.2 +/- 4.4 years, isolated femoris (75.2%), occurring a match (47.3%). median missed per 11.0 days, 28.2% resulting in no days missed, 52.7% classified mild moderate (4-28 days), 19.2% severe (29-744 days). Average number games practices 1.3 2.3 4.0 7.5, respectively. Mean significantly 17.6 occuring 2010-2015 23.9 2016-2021 (p < 0.001). Overall re-injury 52.4% (643), following previously index injury. Reinjury did not change (50.2% vs. 51.6%, p = 0.4506). Factors prolonged sport acute onset (27.8 vs 21.9, 0.023), (24.9 13.2, <0.001). Position, field type, weather conditions, in-game statistically significant. Conclusions: Between one most common causes athletes. Acute RTP 27% (P 0.023) 89% 0.0001), Furthermore, 2010- 2015 seasons 35.7% (p<0.001). current findings emphasize need continued prevention post-injury rehabilitation protocols expectations. high 50% likely contributes longer timelines before however, further study is warranted given rates decrease. [Table: see text]