Functional volleyball spike-jump landing biomechanics and injury incidence of adolescent female club volleyball athletes

Abstract

Purpose: To functionally investigate volleyball spike-jump landing biomechanics in adolescent female club volleyball athletes to determine injury risk factors, and injury incidence. The independent variables were knee injury history (previously injured knee, PIK, and Non-injured knee, NIK) and landing leg (Dominant and Non-dominant legs). Dependent variables were lower extremity kinematics and kinetics. Methods: We used a causal-comparative retrospective research design to identify associated knee injury risk factors. Subjects were 40 highly trained adolescent female club volleyball athletes who completed a retrospective injury questionnaire. Six high-speed three dimensional motion capture cameras and two force plates were used to collect kinematic and kinetic data. Two way analyses of variance (ANOVA) linear model (P < 0.05) were used to analyze two independent (injury status) and six dependent (knee flexion angle at initial ground contact (IC), knee flexion angle at maximal vertical ground reaction force (MVGRF), maximal knee flexion angle, MVGRF (N/Kg), time from IC to MVGRF (sec), and loading rate from IC to MVGRF (N/sec) variables. Results: ANOV A findings indicated significant main effects between PIK and NIK in three of the six dependent variables. Subjects with PIKs revealed significantly larger knee flexion angles at initial contact (p = 0.03), exerted significantly greater maximal vertical ground reaction forces (p = 0.029), and significantly greater loading rates (p = 0.0212) compared with NIKs. Results also revealed significant main effects between dominant and non-dominant legs in three of the dependent variables. Dominant leg data results revealed larger knee flexion angles at initial contact (p = 0.0007), larger knee flexion angles at MVGRF (p < 0.0001), and larger MVGRFs (p = 0.0035) than in the non-dominant leg. No interaction effects were indicated in injury status (PIK vs. NIK) or in landing legs (dominant vs. non-dominant).