CONTRIBUTION OF THE JOINT TORQUE OF THE TAKEOFF LEG IN THE LONG JUMP

Abstract

The purposes of this study were to investigate effects of the joint torques of the takeoff leg on the GRFs in the long jump and to obtain suggestions to long jumpers’ training. The subjects were ten male university long jumpers. Three-dimensional coordinates and ground reaction forces (GRF) were collected by Vicon cameras and a force platform. The force components of the joint torque of the takeoff leg were calculated by a multi-body dynamic method. The results in this study revealed that functions of the hip extensors and abductors seemed to obtain the vertical GRF and to maintain the position of the upper body throughout the takeoff phase. The knee extensors prevented the knee joint from collapsing and bear the body, and the ankle planter flexors played a major important role to generate the vertical GRF.