EFFECT OF LOAD POSITIONING ON THE KINEMATICS AND KINETICS OF WEIGHTED JUMPS

Abstract

The present study sought to examine the effect of altering the position of external loads on the kinematics and kinetics of weighted vertical jumps in 29 resistance trained rugby union athletes. Vertical jumps were performed with loads of 20, 40 and 60% squat 1RM with the load positioned: 1) on the posterior aspect of the shoulder using a traditional barbell (TBJ); and 2) at arms’ length using a hexagonal barbell (HBJ). Weighted jumps performed with the load held at arms’ length resulted in significantly greater values for jump height, peak force, peak power, and peak rate of force development (p<0.05), indicating a greater training stimulus for the HBJ than TBJ. These results suggest that when using weighted vertical jumps to improve lower body muscular performance, the jumps should be performed with the external load at arms’ length rather than on the shoulder.