EFFECTS OF APPROACH VELOCITY TO THE CONTRIBUTION OF EACH BODY SEGMENTS TO THE TAKE-OFF MOVEMENT IN THE LONG JUMP

Abstract

INTRODUCTION Much study suggested that approach velocity gave significant effects to the long jump performance However, there are very few studies effects of approach velocity to the role or the contribution of each body segments to the take-off movement in the long Jump, which is the purpose of this study Nine male long jumpers performed the long jump of the three types, Slow jump (S 10----15m-approachrun), Medium jump (M 25----30m-approachrun), Fast jump (F full approach of their own). Their take-off motions were filmed at 200Hz with Nac high speed camera. Two dimensional coordinates were obtained by digitizing the motions with a sampling frequency of 200Hz. The data was filtered with a Butterworth digital filter(Winter 1979) at 10Hz BSP of Chandler et al. (1975) were used to estimate the segmental centers of gravity and mass center of the whole body This data used to calculate the generated momenta and impulses (horizontal, vertical) of the arms (A), trunk (T: head and trunk), free leg (F) and take-off leg (TL), using the method of Ae and Shibukawa (1980). The mean percent contribution of the segments were obtained by dividing total impulse of each segment over the take-off phase by the whole body impulse RESULTS With the regard to the horizontal direction, the body segments contribution suggested the same proportion pattern all of the three types jumps. The highest (positive) contribution was made by the trunk (S: 4155±22.5%, M36.42± 18.23%, F54.85 ± 3024%) The contribution of the arms (S -5.97±281%, M:-6.34±5.21%, F:-9.54± 6.20%), The free leg (S: -5.85±481%, M: -1603±1120%, F: -722±3.10%) and take-off leg (S:-129.73±35.59%, M -11405±48.47%, F:-138.10±6550%) were negative. Most negative contribution was made by the take-off leg As for the vertical direction, the all body segments contribution of the three types jumps showed positive contribution (S; A 4.29±262%, T 4.06±423%, FL 0.69± 2.44%, TL 90 96±7.82%, M; A 600± 1.60%, T 9.54±9.37%, FL 010±210%, TL 84.36±11.14%, F; A 10.5±3.12%, T 8.02±604%, FL: 2.88±1.01%, TL 78.60 ± 14.56%). The take-off leg showed the highest percentage contribution As the approach velocity increased, so did the contribution of the arms, while the contribution of the take-off leg decreased. CONCLUSION With regard to the horizontal direction, the body segments contribution showed the same proportion pattern in all of the three types jumps The trunk made positive contribution to horizontal velocity, the trunk made positive contribution to horizontal velocity, the other body segments made negative contribution to horizontal velocity in horizontal direction. On the other hand, as the approach velocity increased, so did the contribution of the arms, while the contribution of the take-off leg decreased. The arms and take-off leg have a mutually supportive relationship in vertical direction.