Kinematic Analysis On The Last Two Strides Of Approach And Take-off Technique Of Chinese Elite Male High-jumpers

It is important to analysis and diagnosis on the last two strides during approach and take-off technique of Chinese elite male High-jumper for improving their high-jumping ability. Four male athletes attended the 2005"Jiang Lan Cup"of National Trak-and-Field competition series in Yixing and Asian Track-and-Field opening competition of male high-jumping were selected as our subjects .Two JVC9800 high-speed cameras were used to take synchronism image of the last two stride during approach and take-off technique in 50fps and analyzed the images in the SIMI-motion video analytical system.The results shows: (1) Four male athletes have a lower horizontal velocity in the last two strides. Three subjects'pace of last two strides during approach was in reason. (2) Athletes'centre of gravity loci were smooth and the fall in angle of their body range from to small that was the contrary with foreign elite high-jumpers in the last two strides during approach. The change of the height of the Body's centre of Gravity was large in the last one stride. During the take-off , with the take-off leg touching the ground, the height of the Body's centre of Gravity have a significant difference with foreign elite high-jumpers. (3) In the buffering course of the swing leg, the knee joints of tried legs partly buffered too much , and the range of stretch is too small. The ability of finishing the swing leg was weak and this made the horizontal velocity lower. Those factors were harmful to remain the run-up speed and take-off effect. Both the distance of the last stride and the rate of last-stride distance and the body were comparatively small, having a significant difference with foreign elite high-jumpers. Buffering technique of one of the athletes was in reason. Four male athletes were that it take-off leg lip,knee,ankle 3 joint fully pedal and stretch in the twingkling of an eye to finish to take-off to try. Chinese jumper's the height of the left leg at the end of take-off and the height of are lower than that of world level high jumpers. (4) Xu-xin adopted the bent-leg mode, the others adopted the fold-leg mode, during the take-off , the swing leg has a smaller amplitude and lower swing speed. Li-bing adopted intersecting of single-arm mode, The others adopted intersecting of double-arm mode. The swing speed of left arm are comparatively small, having a significant difference with foreign elite high jumpers.