Isometric single-joint rate of force development shows trivial to small associations with jumping rate of force development, jump height, and propulsive duration

Objectives

The association between single-joint isometric rate of force development (RFD_ISO) and jumping outcomes remain largely unexplored. Further, the importance of RFD assessed during jumping for jump height and duration (i.e. time from jump onset to take-off) remains ambiguous. We therefore investigated these associations in a large heterogenous sample.

Design

Cross-sectional study.

Methods

Three-hundred-twenty-six male and female basketball and tennis players, and physical education students performed the bilateral squat jump (SJ) and both bilateral and unilateral countermovement jumps (CMJ). Single-joint RFD_ISO was assessed for the hip extensors, knee extensors and ankle extensors and associations between relevant outcomes were computed.

Results

Knee and hip extensors RFD_ISO showed small positive correlations with RFD_SJ and RFD_CMJ. Ankle extensors RFD_ISO showed a moderate positive correlation with RFD_SJ and RFD_CMJ. RFD_ISO showed small to moderate correlations with CMJ and SJ jump height, but trivial correlations with jump duration. Stepwise linear regression showed that a combination of RFD_ISO from different muscle groups explained a small to moderate variance in jump height (∼23–28%), duration (∼2–3%), and RFD during jumping (∼19–28%). RFD_SJ showed small positive and moderate negative correlations with SJ height and duration, respectively while these correlations were small and trivial for the CMJ.

Conclusions

The positive correlations between RFD during jumping and jump height, and negative correlation with jump duration imply that improving RFD during jumping could benefit jump performance. However, the mostly small correlations between single-joint RFD_ISO and jumping RFD suggests that single-joint RFD_ISO assessments provide only limited information regarding the RFD in sports-related movements.