DYNAMIC MODEL OF HOP-STEPJUMP TECHNIQUES IN THE TRIPLE JUMP

This paper established a dynamic model of hop-step-jump techniques in the triple jump. The model analyzed the relationships among the dynamic reaction forces during landing and take-off phases, vertical jumping velocity, horizontal jumping velocity and provided a theoretical guide for developing jump techniques. A flow diagram was designed for the body Centre of Mass (C of M) velocity changes. Based on these hypotheses, we attempted to find the relationships among those variables and developed new techniques which are in keeping with the relationship. To resolve the hop-step-jump technique according to these hypotheses, we utilized mathematic and mechanic methods to deduce respectively the body C of M variations and the body bearing forces during the landing and take-off phases of hop, step and jump procedures. Based on those formulas, we studied the relationships among the variables and presented a dynamic model of hop-stepjump techniques in the triple jump. The model demonstrates that the take-off techniques decrease the horizontal velocity as much as possible during landing and increase the horizontal velocity as much as possible during take-off