Tae Kwon Do Yeop-Jireugi With Back Leg On The Perspective Of Kinematics Analysis

Presently, there are a few documents and journals about Tae kwon do research both here and abroad, the people abroad focus only on sports damage and medical rehabilitation, we mainly study in how to select excellent athletes, the indexes of physiology and biochemistry, application of tactics, sports damage and so on in China. In resent years, we can find some materials about basic technique and characteristics of muscle group work. Probably, one of the reasons is that development and generalization of Tae kwon do is too short in the word. In the same time, it is difficult to find some papers in respect of sports biomechanics methods. Yeop-Jireugi technique is one of the most important means to get scores, the percentage of Yeop-Jireugi scoring of male and female respectively, 85.58% and 66.95%. The paper adopts the method of image measurement and analysis to get kinematics parameter and data of excellent Tae kwon do athletes in China. Then, the paper applies biomechanics theory and methods to study Yeop-Jireugi with back leg technique of them, to find the mainly factors that influence this technique, establish correct conception of Yeop-Jireugi with back leg and action configuration. In this way, more perspectives are involved in the study to provide theoretical foundation for the evaluation of skill of these excellent athletes, to short the time of teaching and period of training. through the above analysis and studies, such conclusions are got:the time of the whole Yeop-Jireugi with back leg is 0.32 s ± 0.03, starting time is 0.07s ± 0.01, kicking time is 0.08 ± 0.02 s; On observing the changing of joint angle, there is a wave crest between the stages of starting and lifting knee in the changing of hip angle, the range of the whole augment is 14.3o± 5.0, and down off 99.0o± 3.4, included angle of thigh and shank of male and female athletes is only 76.8o± 7.5, knee joint angle of most athletes can not unbend on the moment of foot touching target; The speed curve of hip joint of the excellent athletes has two wave crests in speed changing of very joint angle of sway leg, the trend of joint speed changing about hip and knee is "ordinary-faster-fast", the biggest speed of ankle appear before touching target and not when touching; Enhancing highness of the center of gravity through lifting heel and extending knee, there is a trend for support leg of excellent athletes to glide forward; sequence of the action predecessor provided is "lifting knee, rotating coax, kicking", however, this study got the result " rotating coax--lifting knee, lifting knee, kicking"; this study find the center of gravity is not staying at the supporting leg, through dynamic equilibrium to maintain stabilization of human body relatively, the trend of speed changing of center of gravity is " ordinary-fast-faster", this characteristic accords with the traditional experience of kicking the enemy with your weight.