Acute effect of bounce drop jump and countermovement drop jump with and without additional load on jump performance parameters and reactive strength index on young gymnasts

Abstract

Purpose.Reactive strength index defines an athlete’s stretch-shortening cycle function and rebound capabilities. The purpose of the study was to examine the effect of two types of drop jumps (bounce drop jump: BDJ and countermovement drop jump: CDJ) on the jump parameters and reactive strength index under two different conditions (with and without additional load) from different drop box heights.Methods.Twelve female artistic gymnasts aged 10–12 years old volunteered to participate in this study. Drop jumps (DJ) were performed from 20-, 25-, 30, and 35-cm heights under two conditions: without additional load (FREE) and with additional load (VEST).Results.No interaction effect was found between the drop jump height, drop jump type and condition parameters, between the drop jump type and load parameters, or between the drop jump height and condition parameters. However, an interaction effect was observed between the drop jump type and load parameters for the reactive strength index. The drop box height (DBH) did not affect any of the dependent variables and the drop jump type with the VEST condition was more effective in improving the examined variables.Conclusions.The CDJ produces a lower reduction in the jump height under both the FREE and VEST conditions from different DBHs with an optimum DBH of 30 cm, while stiffness can be improved with both types of jumps from a DBH 25 cm. The characteristics of jumps, such as BDJ and CDJ and DBH, are determinants of the resulting jump height.