Rapid Spike in Hip Adduction Strength in Early Adolescent Footballers: A Study of 125 Elite Male Players from Youth to Senior

Purpose: To investigate the differences in hip adductor and abductor muscle strength in elite male footballers from youth to senior level. Methods: We tested 125 players from the under-13-years (U 13) to senior squads of a Danish male professional football club in this cross-sectional design study. Hip adductor and abductor force (in newtons), torque (in newton meters), normalized torque (in newton meters per body mass), and adduction-To-Abduction ratio were measured using handheld dynamometry. Results: Between U 13 and senior level, adductor force increased by 104%, torque by 127%, and normalized torque by 21%. Abductor force increased by 78%, torque by 126%, and normalized torque by 17%. For incremental differences between age groups, significant increases were observed between the ages ofU 13 toU 14 (18% 39%) andU 14 toU 15 (19% 33%) for all strength measures (P .021). No incremental difference was observed for adductor-To-Abductor ratio. Conclusions: The large increases in hip adductor and abductor strength occurring between the ages of U 13 andU 15 offer insight into the strength capabilities and stress demands in these players, which may relate to injury vulnerability, and facilitate clinicians in selecting best-suited exercise interventions.