Study On The Kinematic Characteristics Of The Final 5-meter Run-up Speed And The Skills Of Single Foot Jump And Stride Jump Of Chinese Elite Male Triple Jumpers

Chinese men's triple jump has become one of the most important events in the world through the efforts of several generations.The technical characteristics of triple jump are as follows: the athletes run up quickly and complete three technical movements of single-foot jump,step jump and jump while keeping the horizontal speed as far as possible.No technical and details of triple jump are allowed to cause problems or it will lead to the failure of the trial jump and the decline of the results.This requires athletes to have strong special physical ability and excellent technical characteristics.In 2016,China's Dong Bin won the third place in the Rio Olympic Games with 17.58 m.In the Rio Olympic Games,three Chinese athletes entered the final of triple jump at the same time,which shows us the progress of Chinese men's triple jump.In view of this,the kinematics analysis of Chinese Elite Male Triple Jumpers is of great significance to improve the performance of Chinese men's triple jump.In this paper,the kinematics characteristics of the last 5-meter run-up speed and single-foot jump and step jump techniques of the top eight men's triple jumpers who entered the final of the 2018 National Track and Field Championship(Taiyuan)are taken as the research objects.The whole course of the final is fixed-point shooting with Sony EX-280 high-speed camera.The joint angles and run-up speed are collected by Dartfish image processing software in Switzerland.Through video shooting,mathematical statistics,comparative analysis,film image analysis and other research methods,the technical parameters of the eight athletes in this competition are obtained.By comparing with the technical parameters of the top eight athletes in theworld in the past 10 years,the problems existing in the technical aspects of Chinese men's triple jump athletes are analyzed.The results show that:(1)The speed characteristics of Chinese men's Triple Jumpers in the last5-meter run-up stage are as follows: the speed of 0-3 M stage is more stable than that of 3 m-5 m stage,and the speed of two athletes decreases;the last two steps show the trend of "big-small",but there are significant differences in speed and stride length with the world athletes.The main reason for the decline of run-up speed of Chinese athletes in the final stage is that they can not have the matching lower limbs and the maximum strength of the whole body.(2)The Chinese Male Triple Jumpers show the characteristics of small ground angle,slightly larger angle between two legs,and basically the same trunk forward tilt angle as the world's athletes in the stage of single-foot landing;the knee angle and hip angle in the buffer stage are larger than those of the world's athletes,but there is a significant difference between the buffer range and the world's athletes;and in the stage of kicking and stretching,they show that the knee angle deviates from the ground is not active and the kicking and stretching is not Full,lack of ability to control the take-off angle.There are some problems in Chinese athletes,such as poor quality of special strength and poor ability of landing support for quick take-off.(3)Chinese Male Triple Jumpers have smaller trunk forward tilt angle in stride jump,and can not maintain upper body integrity.Early straightening of takeoff leg results in inadequate "picking up the ground",and the knee,hip and ankle buffer range in buffer stage is smaller than that of the world athletes;the knee pedal stretch range is quite different from that of the world athletes,reflecting the special strength and strength of lower limb muscles of Chinese athletes.Flexibility is poor.(4)There is no significant difference between Chinese athletes' single-foot take-off and pedal angle of 8.67 degrees and world athletes' 9.94 degrees.The gap between Chinese athletes and world athletes is large,which indicates that Chinese athletes' ability to maintain horizontal speed in step jump is poor,their swinging legs are not active,their center of gravity can not move forward quickly,and they can not obtain effective pedal and stretch strength.(5)In terms of take-off time,the first two jumps of Chinese athletes are characterized by longer buffer time,shorter pedal and stretch time,and longer total support time.This shows that improving the last 5-meter run-up speed,increasing absolute speed and matching the maximum strength of lower limbs and whole body is the focus of future training for Chinese athletes.