Concentric hip work is the most robust lower-limb kinetic correlate of depth-jump height in male collegiate volleyball players

Abstract

Abstract Background Depth-jump height is commonly used to assess lower-limb explosive performance, but it remains unclear which phase-specific hip, knee, and ankle joint kinetic variables are most consistently associated with performance in volleyball players. Methods In this cross-sectional movement-analysis study, thirty male collegiate volleyball players completed height-oriented depth-jump tests from a standardized 30-cm box. Three-dimensional motion capture and two force platforms were used to quantify jump height, hip, knee, and ankle joint stiffness, and peak joint moment, peak joint power, and joint work during the ground-contact braking/eccentric and propulsive/concentric phases. Participants were ranked by jump height and divided into a high-jump group (HJG) and a low-jump group (LJG) using a median split for descriptive comparison, whereas Pearson correlation analysis across the full sample was used as the primary continuous analysis. Benjamini-Hochberg false discovery rate (FDR) correction was applied to account for multiple comparisons. Results HJG achieved greater jump height than LJG. In uncorrected analyses, HJG showed higher concentric-phase peak hip moment, peak hip power, hip joint work, and ankle joint work. After FDR correction, only concentric-phase hip joint work remained significantly higher in HJG than in LJG ( p < 0.001, q = 0.012). Correlation analysis showed that concentric-phase hip joint work had the strongest association with jump height ( r = 0.610, 95% CI: 0.320 to 0.795, p < 0.001, q = 0.007). Concentric-phase peak hip moment, peak hip power, and ankle joint work showed uncorrected positive associations, but these findings did not survive FDR correction. Conclusions Among the variables examined, greater depth-jump height in male collegiate volleyball players was most robustly associated with cumulative positive hip work during the concentric propulsive phase. Supportive uncorrected findings for peak hip moment, peak hip power, and ankle joint work should be interpreted as exploratory. Concentric hip work may be useful as an associative monitoring variable and a candidate for longitudinal mechanistic testing, but the present cross-sectional findings do not establish that increasing hip work will cause improvements in depth-jump height.