LAUSR

Objectives: Early sport-specialization has been shown to place athletes at risk for increased injuries and decreased sporting performance in various sporting populations. However, the effect of sport-specialization has not been studied in professional baseball. The purpose of this investigation is to determine if single-sport athletes that specialize in baseball at a young age have a greater predisposition to overuse injury, burnout, and decreased performance compared to multiple-sport athletes. We hypothesized that MLB players who played multiple sports in high school would experience fewer injuries necessitating time on the Disabled List (DL), play more games, and have a longer career compared to athletes that played only baseball in high school. Methods: First and second-round MLB draft picks from 2008 to 2016 that played in at least one professional (minor or major league) game were included in this study. Athletes who participated in one or more sports in high school in addition to baseball were considered multi-sport athletes, and athletes who participated in only baseball were considered single-sport athletes. For each athlete, participation in high school sports, injuries sustained in MLB and MiLB, number of days on the Disabled List (DL) for each injury, number of games played in MLB and MiLB, and whether the athlete was still active were collected from publically available records. Results: Seven hundred forty-seven athletes were included in this study, of which 240 (32%) were multi-sport and 506 (68%) were single-sport athletes. Multi-sport athletes played in significantly more total professional baseball games on average (362.8 vs. 300.8, p < 0.01) as well as more major league games (95.9 vs. 71.6, p = 0.04) than single-sport athletes. Meanwhile, single-sport athletes had a significantly higher number of upper extremity injuries than multi-sport athletes (136 vs. 55, p < 0.01, Table I). Single-sport pitchers also had a higher number of shoulder and elbow injuries than multi-sport pitchers and, once injured, were more likely to have recurrent elbow injuries (86 vs. 27, p < 0.01; 33% vs. 17% recurrence). Conclusion: Professional baseball players who participated in multiple sports during high school played in more MLB games and sustained fewer upper extremity injuries than players who specialized in baseball before high school. Professional pitchers who specialized by the time they were in high school had a significantly higher chance of sustaining recurrent elbow injuries compared to those who were multi-sport athletes in high school. MLB players with a history of multi-sport participation were more likely to avoid overuse injuries and had greater longevity and level of performance compared to those that limited their sport participation to baseball during high school. Injuries by Body Part Number of Players Single-sport (216) Multi-sport (110) P-value Elbow 42 (19%) 17 (15%) Shoulder 53 (25%) 20 (18%) Forearm 12 (6%) 6 (5%) Wrist 7 (3%) 2 (2%) Bicep 8 (4%) 2 (2%) Hand 14 (7%) 8 (7%) Total Shoulder and Elbow 95 (44%) 37 (34%) p<0.01 Total Upper Extremity 136 (63%) 55 (50%) p<0.01 Total 166 (77%) 65 (59%) p<0.01