Dynamic balance ability during single-leg drop landing across different age groups of junior gymnasts

[Purpose] Dynamic balance and shock absorption during landing are essential for gymnastics performance and injury prevention; however, age-specific landing biomechanics remain unclear. This study examined age-related differences in dynamic postural control and shock absorption during single-leg drop landing (SDL) among junior gymnasts. [Participants and Methods] Forty junior gymnasts (elementary school: n=12; junior high school: n=12; high school: n=16) performed SDL from a 20-cm platform onto a force plate. Peak vertical ground reaction force (Fz), buffering coefficient, and center of pressure (COP) trajectory length during early (20-200 ms) and prolonged (20 ms-5 s) post-landing phases were analyzed. Group comparisons were conducted using one-way analysis of variance or Kruskal-Wallis tests with post hoc analyses. [Results] Significant group differences were observed in all parameters. High school gymnasts showed lower Fz, shorter COP trajectories, and higher buffering coefficients than elementary and junior high school groups. No significant differences were found between elementary and junior high school gymnasts, suggesting a transitional developmental phase with neuromuscular inefficiency. [Conclusion] Dynamic postural control and shock attenuation improve with age in junior gymnasts, particularly after peak height velocity (PHV). Age-specific neuromuscular training may help reduce ankle injury risk and enhance performance.