IS THE LOCAL MINIMUM IN THE FORCE TIME HISTORY IN COUNTERMOVEMENT JUMPS RELATED TO JUMP PERFORMANCE

The purpose of this study was to investigate the relationship between joint kinematics and joint kinetics of the lower extremity to the decrease in the force time curve in counter movement jumps. Thirty-five sports students performed maximum voluntary countermovement jumps. Two force plates and a 10 camera optoelectronic system as well as a full-body model were used to measure joint kinematics and kinetics. Twelve subjects showed a characteristic double peak in force-time-history in the concentric phase. This pattern was not directly related to jumping height. However the time for the total movement cycle as well as for the concentric phase of the jump was longer. In some sports it is necessary the produce maximum impulse in the concentric phase in a short period of time. In those cases a different movement strategy might be beneficial.