Sports Biomechanics Study On National Female Elite High Jumpers-Gu Biwei, Shen Qinli's Take-Off Skill

By using the Simi Motion system and the Novel Pedar-x insole system, our nation's 2 elite female high jumpers' penultimate stride and take-off skill were studied. The parameters acquired were to make comparison with the foreign elite high jumpers. The results are as follows:From the viewpoint of run-up trait, 3 striding marks of the last two steps before taking off shaped an obtuse triangle. The stride length becomes shorter before taking off. The reliability of Gu Biwei and Shen Qinli's run-up skill is at a high level.Gu Biwei, Shen Qinli's velocity of center gravity when last landing are 5.90 m/s, 5.54m/s respectively, which are lower than world elite female high jumpers. While Gu Biwei has a large vertical velocity at the point of taking off, Shen Qinli's vertical velocity is much lower than world jumper.Compared with foreign jumpers', our national jumpers have a higher rate in usage of run-up speed. To be more concrete, the rate of vertical velocity while taking off to the total velocity at last landing before taking off are 63.051%, 61.191% respectively.Our national high jumpers' body height is no shorter than foreign athletes, but a lower value in H₁ and Hi/body height. The exactly values of three athletes are Shen Qinli's 1.30m and 71.61%, Gu Biwei's 1.22m and 68.73%.At the point of taking-off our national's 2 jumpers' hip joint angle, knee joint angle and ankle joint angle are lower than those of foreign high jumpers'. AS the taking-off time of the jumpers of our nation is concerned, are in the range from 0.120 s to 0.200s, from which were classified as Speed Type.On the total maximum level of feet's pressure of Gu Biwei is lower than that of Shen Qinli. In the process of taking off, the total value of feet's pressure increased rapidly and reached to its first peak 0.02～0.04s after last landing. Then decline until the jumper reached peak buffer. Then increase again , after 0.02s⁰.06S reached to another peak value.The maximum pressure of Gu Biwei and Shen Qinli on single sensor appeared in the area of lateral heel. Generally, the peak pressure on single sensor appears 0s⁰.06s after last landing.On the arrangement sequence of the peak pressure in the 9 foot parts, the peak pressure of the medial heel, lateral heel and the middle metatarsal ranks the first four, while the same value of the medial arch and the area of the great toe ranks the last four. Every jumper displays different characteristics of the other foot parts.During the period of taking off, the lateral heel and medial heel first reaches peak value nearly the same time, among 9 parts of the foot. And the great toe and others toes reaches its peak pressure latest. In other parts of 9, the arrangement sequence turns unregulated.