RESEARCH

Youth Single-Sport Specialization in Professional Baseball Players. 

Orthopedic J Sport Med. 8(3): 1-8, 2020.

Background: An increasing number of youth baseball athletes are specializing in playing baseball at younger ages.

Purpose: To describe the age and prevalence of single-sport specialization in a cohort of current pro baseball athletes. In addition, the researchers sought to understand the trends surrounding single-sport specialization in pro baseball players raised within and outside the United States (US).

Study Design: Cross-sectional study; Level of evidence, 3.

Methods: A survey was distributed to male pro 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. The following data were analyzed:

• Rate and age of specialization

• Reasons for specialization

• Athlete’s perception of injuries related to specialization

Results: 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 pro athletes specialized in playing a single sport during their childhood/ adolescence

• Those who specialized 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 players native to the US (12.30 ± 3.07 vs 14.89 ± 2.24 years, P < .001).

• MLB players raised in the US recalled a significantly higher incidence of sustaining an injury attributed to specializing in baseball than MLB athletes raised outside the US (27.7% vs 20.6%, respectively; P < .05).

Conclusion: This study challenges the current trends toward early youth sport specialization, finding that the majority of pro 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.