Sport Specialization and Risk of Overuse Injuries: A Systematic Review With Meta-analysis

CONTEXT: Sport specialization is theorized to increase the risk of sustaining overuse musculoskeletal injuries. OBJECTIVE: To complete a systematic review and meta-analysis of the literature to determine if sport specialization is associated with overuse musculoskeletal injuries. DATA SOURCES: An electronic search was conducted using the search terms “specialization,” “year-round,” “overuse,” “repetitive stress,” “injury,” “young,” “pediatric,” and “sports.” STUDY SELECTION: Studies were included if their population was ≤18 years of age, if they compared athletes with high or single-sport specialization with athletes with low or multisport specialization, and focused on overuse injuries. DATA EXTRACTION: Of the 12 articles that were identified for full-text review, 5 studies met all the inclusion criteria. Four studies provided adequate data for the meta-analysis. Quality scores on the modified Downs and Black scale ranged from 69% to 81%. RESULTS: Athletes with high specialization were at an increased risk of sustaining an overuse injury compared with athletes with low (pooled relative risk [RR] ratio: 1.81; 95% confidence interval [CI]: 1.26–2.60) and moderate (pooled RR: 1.18; 95% CI: 1.05–1.33) specialization. Athletes with moderate specialization were at a higher risk of injury compared with athletes with low specialization (RR: 1.39 [95% CI: 1.04–1.87]). LIMITATIONS: Four of the 5 studies included in this systematic review were included in the meta-analysis because of the lack of access to the original data set for 1 article. CONCLUSIONS: Sport specialization is associated with an increased risk of overuse musculoskeletal injuries (Strength of Recommendation Taxonomy grade: B).