Abstract
Background/Objectives: Mixed martial arts (MMA) is a combat sport which heavily involves upper limb strength, mobility, and stability. Shoulder injuries, given their impact on striking and grappling, may significantly hinder performance and career longevity. However, their specific effects on competitive outcomes remain poorly defined. This study evaluates return-to-sport rates, fight performance, and long-term success in professional MMA athletes following shoulder injuries. Methods: A retrospective cohort study was conducted using publicly available databases to identify professional MMA fighters from the UFC, Bellator, and Strikeforce who sustained shoulder injuries requiring withdrawal from scheduled bouts. Fighter demographics, injury characteristics, and treatment approaches were recorded. Performance metrics-including winning percentage, takedown (TD), knockdown (KD), and significant strike (SS) rates-were compared before and after injury. Independent t-tests were used, and significance was set at p < 0.05. Results: A total of 27 fighters with 34 documented shoulder injuries were included. The most common injury was a torn labrum (41.2%), with 76.5% requiring surgical intervention. Aggregate winning rates significantly declined from 81.96% pre-injury to 54.7% post-injury (p < 0.001). Aggregate KD rates also dropped significantly (p < 0.001), while TD rates trended downward without reaching statistical significance. SS rates remained stable, suggesting potential compensatory mechanisms. Injury recurrence was observed in 22.2% of cases. Conclusions: Shoulder injuries in MMA are associated with a substantial decline in competitive success, particularly in knockout capability, emphasizing the critical role of shoulder integrity in fight performance. The high recurrence rate suggests the need for optimized rehabilitation protocols and stricter return-to-sport guidelines to enhance fighter longevity.