A BIOMECHANICAL ANALYSIS OF THE SUPPORT MECHANISM OF THE TAKEOFF LEG IN THE LONG JUMP

The purpose of this study was to investigate the function of the takeoff leg as a support mechanism in the long jump with the mechanical model (Shibukawa et aI., 1966). The mechanical model assumed that the force exerted by the takeoff leg was equivalent to the sum of the spring, damper and jack forces. Eleven male long jumpers participated in this study. Large spring and damper forces were exerted and absorbed the impact force immediately after the touchdown, and the spring force was also exerted around 25 to 80% of the takeoff phase. The jack force was dominant in two thirds of the takeoff phase. The comparison between the elite jumpers and the ordinary college level jumpers indicated that larger spring force around 25 to 50% of the takeoff phase of the ordinary college level jumpers would result from larger knee flexion