Bell et al. 2018, Sport specialisation and risk of overuse injuries: systematic review and meta-analysis

This systematic review and meta-analysis published in Pediatrics (Vol. 142, No. 3: e20180657), pooling data from over 3,000 young athletes, found a dose-response relationship between sport specialisation and overuse-injury risk: highly specialised athletes had greater risk than low-specialisation athletes (RR 1.81, 95% CI 1.26–2.60) and than moderately specialised athletes (RR 1.18, 95% CI 1.05–1.33), and moderately specialised athletes had greater risk than low-specialisation peers (RR 1.39, 95% CI 1.04–1.87). The findings provide quantified, pooled evidence that early single-sport specialisation meaningfully elevates overuse-injury risk in youth. Moderate evidence.