Youth Single-Sport Specialization in Professional Baseball Players.

An increasing number of youth baseball athletes are specializing in playing baseball at younger ages. The purpose of our study was to describe the age and prevalence of single-sport specialization in a cohort of current professional baseball athletes. In addition, we sought to understand the trends surrounding single-sport specialization in professional baseball players raised within and outside the United States (US). Cross-sectional study; Level of evidence, 3. A survey was distributed to male professional baseball athletes via individual team athletic trainers. Athletes were asked if and at what age they had chosen to specialize in playing baseball at the exclusion of other sports, and data were then collected pertaining to this decision. We analyzed the rate and age of specialization, the reasons for specialization, and the athlete's perception of injuries related to specialization. A total of 1673 professional baseball athletes completed the survey, representing 26 of the 30 Major League Baseball (MLB) organizations. Less than half (44.5%) of professional athletes specialized in playing a single sport during their childhood/adolescence. Those who reported specializing in their youth did so at a mean age of 14.09 ± 2.79 years. MLB players who grew up outside the US specialized at a significantly earlier age than MLB players native to the US (12.30 ± 3.07 vs 14.89 ± 2.24 years, respectively; This study challenges the current trends toward early youth sport specialization, finding that the majority of professional baseball athletes studied did not specialize as youth and that those who did specialize did so at a mean age of 14 years. With the potential cumulative effects of pitching and overhead throwing on an athlete's arm, the trend identified in this study toward earlier specialization within baseball is concerning.

© The Author(s) 2020.

One or more of the authors declared the following potential conflict of interest or source of funding: P.S.B. has received educational support from Smith & Nephew (provided to the Steadman Philippon Research Institute), Arthrex, and Sea Pearl. M.C.C. has received educational support from Liberty Surgical. M.B. has received educational support from Smith & Nephew (provided to the Hospital for Special Surgery) and Arthrex and hospitality payments from Stryker. P.K. has received educational support from Smith & Nephew (provided to the Steadman Philippon Research Institute), Arthrex, and Supreme Orthopedic Systems; fellowship support from DJO; and speaking fees from Smith & Nephew. W.E. has received educational support from Liberty Surgical. K.B.F. has received consulting fees from DePuy/Medical Device Business Services, speaking fees from Aastrom Biosciences and Vericel, educational support from Liberty Surgical, and honoraria from Vericel. S.H. has received educational support from Arthrex and Liberty Surgical and hospitality payments from Smith & Nephew. S.B.C. has received speaking fees and consulting fees from Zimmer Biomet. M.G.C. has received educational support from Liberty Surgical, has received research support from Arthrex, is a paid consultant for Stryker, and has stock/stock options in Venture MD. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.