Injury risk and its relationship with biological maturation among 100 junior tennis athletes: a 15-year retrospective...

To investigate injury risk and its relationship with biological maturation in junior tennis athletes.

Data were retrospectively collected from 100 junior tennis athletes (50 boys and 50 girls) over 15 competitive seasons (2006-2021) at a tennis academy. Biological maturation was assessed using peak height velocity (PHV) and age at PHV (APHV). Athletes were classified into five maturity phases: Phase 1 (>18 months before APHV), Phase 2 (18-6 months before APHV), Phase 3 (6 months before and after APHV), Phase 4 (6-18 months after APHV) and Phase 5 (>18 months after APHV). The relationships between maturation and injury incidence or burden (days lost per year) were analysed as primary and secondary outcomes using regression analysis with Zero-inflated Poisson model adjusted for sex and phase, with estimated minimum training volume considered during model building.

The mean APHV and PHV were 13.2 years (range 11.1-15.7) and 96.3 mm/year (91.1-103.2) for boys and 11.5 years (9.3-13.7) and 92.3 mm/year (79.9-98.7) for girls, respectively. Sex differences were observed for both indicators. A total of 256 injuries were recorded. In boys, the highest incidence (1.34 injuries/year, 95% CI 0.57 to 1.84) and burden (16.4 days/year, 95% CI 3.04 to 36.94) occurred in Phase 3, both higher than in Phase 1. In girls, the highest incidence (0.98 injuries/year, 95% CI 0.75 to 1.32) and burden (7.2 days/year, 95% CI 2.24 to 18.82) were in Phase 5, also higher than in Phase 1.

Injury incidence and burden varied across APHV-based maturity phases and differed by sex, with the highest injury risk observed around APHV in boys and after APHV in girls. The wide interindividual range in APHV (4.5 years) highlights the importance of individualised, maturation-specific and sex-specific injury prevention strategies in junior tennis athletes.