The Three-dimensional Kinematic Analysis On Both The Last Two Stride During Approach And The Takeoff Technique Of The Youthful Male High-jumpers In JiangSu

It is most important meaning that the fosbury flop technique of the youth is analyzed and diagnosed to improve the whole level of our high-jump. To select six athletes who enter the male chia-group high-jump finals as my research object in the youth track and field events of Jiangsu province. To use two JVC9800 high-speed cameras took synchronism image in l00fps and analyzed the images in the SIMI-motion video analytical system. The results as follows: (1) the post-three-move run-up speed is small -large- middle rhythm, most of players have the longer last stride and longer time than the last second step, the vertical velocity of body's center of gravity is positive when the take-off leg is touchdown during the last step, the ripple of body's center of gravity is a little bigger during the last two steps. The run-up technique and velocity rhythm is detrimental to the take-off. ( 2 ) The velocity conversion factor is lower, the angle of the shank and groud and the hip angle is larger the instant of the take-off leg touchdown during the phase of take-off, the range of buffer of hip and knee and ankle is smaller, the ranger of stretch of hip and knee and ankle is not enough, the take-off time is longer. Those factors are harmful to remain run-up speed and take-off. (3) During take-off, the majority players' swing leg and arms adopt respectively the swing way of the bent-leg and two arms swing simultaneously, the swing leg and arms are not match harmoniously, the speed of swing leg is slow and the range ofAbstractit is lower, Those affects directly the result of swing . (4) The toe-in angle of the upper body is not enough the instant of the take-off leg touchdown, the empty time is longer. Those factors influence the stretch of body and the result of take-off.