Altered landing mechanics are shown by male youth soccer players at different stages of maturation

Objectives Examine the effects of maturation on single leg jumping performance in elite male youth soccer players. Design Cross sectional. Setting Academy soccer clubs. Participants 347 male youth players classified as either pre, circa or post-peak height velocity (PHV). Main outcome measures Single leg countermovement jump (SLCMJ) height, peak vertical landing forces (pVGRF), knee valgus and trunk side flexion. Results Vertical jump height and absolute pVGRF increased with each stage of maturation (p < 0.001; d = 0.85–2.35). Relative to body weight, significantly higher landing forces were recorded on the left leg in circa versus post-PHV players (p < 0.05; d = −0.40). Knee valgus reduced with maturation but the only notable between-group differences were shown in post-PHV players (p < 0.05; d = 0.67); however, greater ipsilateral lateral trunk flexion angles was also present and these differences were significantly increased relative to circa-PHV players (p < 0.05; d = 0.85). Conclusion Periods of rapid growth are associated with landing kinetics which may heighten injury risk. While reductions in knee valgus were displayed with maturation; a compensatory strategy of greater trunk lateral flexion was evident in post-PHV players and this may increase the risk of injury