Prediction of individual optimal drop height in drop jump from anthropometric and strength variables

This study aimed to investigate the associations between individual optimal drop height (ODH), as determined by the reactive strength index (RSI) method, and selected anthropometric and strength parameters, and to develop a prediction model for ODH based on these variables. A total of 49 participants were recruited, and measurements included body height, body mass, maximal muscle strength (MSmax), lower limb stiffness, reactive strength ratio (RSR), countermovement jump (CMJ) height, and ODH. Pearson correlation analysis was conducted to examine the relationships between ODH and the assessed variables. A multiple linear regression model was constructed in a stepwise manner to predict individual ODH. Significant correlations were observed between ODH and relative MSmax (r = 0.827, P < 0.001), RSR (r = 0.703, P < 0.001), body mass (r = -0.481, P < 0.01), body height (r = -0.430, P < 0.01), and CMJ height (r = 0.487, P < 0.01). Relative MSmax, CMJ height and RSR collectively explained 78.4% of the variance in ODH (R² = 0.784). The final prediction equation was: ODH = -45.602+31.027*relative MS_max +0.548*CMJ height +5.549*RSR (R² = 0.784, F (3, 36) = 48.190, p < 0.001). Coaches should consider body height, body mass, RSR, relative MSmax, and CMJ height when prescribing drop jump height. Moreover, an individual's ODH should be adjusted when changes in CMJ height or relative MSmax occur. Finally, this study provides a practical prediction equation for estimating individual ODH using relative MSmax and CMJ height as input variables.