The Three-dimensional Kinematic Analysis Of The Technique Of Swing And Sent Hip In Take-off Process Of Our Country Excellent Men Long-jump Athletes

The technique of long jump is mainly from run-up, take-off, fly and land a four-part composition, the take-off is a continuation of the run-up, is the turning poin of athletes from the sports movement into a parabolict, in the long jump technique is the most critical stage.Its main task is to minimize the loss of horizontal velocity, through the take-off leg push rapid stretching in a very short time and body coordination , possible to create the greatest speed of vertical upward, so that the athletes based on physical and technical characteristics of the individual to create reasonable initial flight speed and the best point of view. The quality of take-off affects not only the technology available and the quality of ground movements, but also able to take full advantage of the level of run-up to gain speed, vertical and horizontal velocity to the speed of the transformation to create the best performance.In this paper, the study's main content is: the technical characteristics of the lower extremities and hip swinging leg in the process of the long jump take-off stage; the relevance of research results of lower limb and hip swing long jump technique in the take-off the process; the relationship research between the lower limb swing and hip technology and the speed of the plate, the body center of gravity Teng initial speed, the level of take-off speed, vertical speed and the the height of flight .In this study, selected to participate in October 14, 2008 National Track and Field Championships (Hebei Shijiazhuang Station) before the eight men's long jump athlete for the study, mainly in literature, the three-dimensional motion video analysis method, survey method, statistical method and mathematical logic Analysis carried out on the analytical study and analysis, research results show that:1 China's best long jumpers, has his own technology characteristics and style, but compared to the world's best long jumpers in the take-off especially in the lower extremities is technically before the hip and technically there is still a certain gap.2 The lower limb and hip sway in the long jump take-off stage of the process performance has a great impact, and lower extremities and hip swing technique have a certain degree of relevance with physical focus initially speed, vertical take-off speed and the level of speed, the height of he body flight center of gravity from the moment t, also has a great impact on performance of the long jump.3 China's best athletes of the men's long jump have the smaller leg hip angle at the moment of take-off board, upward and forward is not positive; swing leg hip angle is more, swinging leg to the side of the swing leg with the hip range is small, swing slowly; swinging leg side of the hip significantly lags behind the front leg, swing leg side to the hip hip belt did not play the role of the legs, leading to the first pendulum swinging leg can not adapt to the rhythm. Shortcomings of these technologies has led to the board angle is small, the angle between the two thighs islarge, a larger trunk inclination to the body center of gravity of the projection points on the ground and supported by a larger distance, resulting in the level of support reaction increased, the utilization of level velocity declined,and that impact on speed performance.4 China's best athletes of men's long jump in the buffer stage, the hip angle of take-off leg is smaller, hip positive, the height of the whole body center of gravity ia upward trend, but the swinging leg is always stressed to accelerate the hip and did not realize the importance of engine-the coxa joint, neglected the acceleration of front action from the coxa joint led to the swinging leg .5 China's best athletes of the men's long jump in the take-off stage, leg extens or leg-side hip forward slowly, ranging small, not enough leg to full and can not put all the power together at the take-off moment, not have the consistent direction send-off,take-off and extend.The body center of gravity exchanged to the upward and forward.The smaller side wing leg hip angle result in a smaller angle of flight.In addition, the long jump as a result of China's athletes to pursue excessive hip forward while ignoring the vertical forced upward, resulting the distance increased between the body center of gravity and the plate to the body center of gravity,the height of flight is fall, and that impact on the long jump performance.