A Biomechanical Study Of The Actual Combat Moments In Flank Kick, Front Kick And Axe Kick Of Women Tae Kwon Do

The present study adopts the SIM MOTION system to make a biomechanical analysis of women contestants in the semi-finals and finals of the China's 2006 National Taekwondo Tournament. Through a period of field work, some important biomechanical parameters to women taekwondo are collected such as duration, angle, velocity, and change of gravity center in flank kick, front kick and axe kick. It aims to discover the differences and similarities and explore the internal structures and laws of those motions in the actual combats in order to provide the quantitative data and theoretical support for the future taekwondo training.The present research finds that:In the flank kick, the three phases of swing leg account for different proportions in the whole moment cycle: the starting stage of raising the knee and rotating the hip occupies 26%, the kicking strike covers 26% and the leg withdrawing stage takes 48%. The champions outperform the other contestants in the starting stage and spend much less time raising the knee and rotating the hip. As for the angles of the moments, there is little difference between, the deviation angles of hips, knees and ankles, in the three phases. Among them., the deviation angle of ankles is relatively larger. The changing amplitude of the vaulting leg is larger but with a steady. change in the entire angle. When it comes to the curves of the changes of hip and knee angles, Lin Ji and Zhang Biyu outdo Wang Ying and Liu Rui. In the respect of velocity curves, the majority of the contestants succeed in attacking with their hips first. Among the contestants,only Wang Ying achieves to "strike fast, withdraw fast, and withdrawing takes less time than strike" in the two velocity peaks of ankles. Still; the gravity center displacement and direction changes with the different actual combats in the flank kick.In the front kick, the three phases of swing leg account for different ? proportions in the whole moment cycle: the starting stage of raising the knee and rotating the hip occupies 24%, the kicking strike covers 25%. and the leg withdrawing stage fakes 51%. The angles are relatively steady in the phases of hip's starting to raise the knee and knee's kicking strike. The joints pf knees and ankles change a lot in the process of the vaulting leg's front kick. In the actual combats, there are active and passive front kicks. It is indicated by the hip curves that there is a distinct angle peak of the,starting stage of raising the knee and rotating the hip in the active front kick. With respect to the hip and knee velocity features, every contestant's body leans forward rapidly in the starting stage and after the knee raising stage. The maximum velocity of the knees appears after the hip joint among the majority of the contestants. Only the two velocity peaks of Jiang Mengfei's ankles approach each other. The gravity center shifts show that the contestants choose the use frequency of the passive front kick as their main strike means in the front kick.In the axe kick, the three phases of swing leg also account for different proportions in the whole moment cycle: the starting stage of raising the knee and rotating the hip occupies 22%, the kicking strike covers 46% and the leg withdrawing stage takes 32%. When it comes to the angle features, in the starting stage there is a rapid forward leaning of the body after the knee is raised similar to that in front kick. So far as the velocity features are concerned, the two peaks in the two different stages of Zhang Qiang and Zong Shaojuan are higher that those of Jiang Mengfei. Yang Ping uses a different means to generate power in strike from the other three contestants. In the respect of the gravity center changes, the displacements of the four contestants' kicking strike are higher than those in the starting, knee-raising and leg-withdrawing stages and they account for as much as a half of the total displacements in the striking process.