Study On The Technical Characteristics And Evaluation System Of Chinese Elite Male Triple Jump Athletes

Objective:The men’s triple jump used to be the dominant event in China,and the Asian record is currently held by Chinese athlete Li Yanxi.Due to the particularity of the long total distance of triple jump and the limited scope of the spatial calibration,the previous studies on the evaluation of men’s triple jump technology were mostly based on the perspective of 2D kinematics,there has not been strict 3D kinematics analysis on it,and the technical evaluation and scoring model of Chinese elite male triple jump athletes has not been established.The purpose of this study is to analyze the 3D kinematics of Chinese elite male triple jump athletes on the basis of large-scale spatial calibration,and to construct the technical evaluation and scoring model of Chinese elite men triple jump athletes on the basis of this to provide theoretical basis for athletic training.Method:Take the 29 effective jumps of 9 athletes who participated in the men’s triple jump final of the 2019 National Indoor Track And Field Championship and the 2020 Chinese Athletic Association Training Base Franchise Competition(Zhejiang)as the research object.This paper makes a 3D kinematic analysis of their triple jump technology by using the methods of 3D photography,motion image analysis and mathematical statistics,and construct the technical evaluation and scoring model of Chinese elite male triple jump athletes.Results:(1)The athletes’ touchdown angle of triple jump is relatively small(62.00±2.90;64.11±3.26;62.46±3.25),not conducive to the maintenance of horizontal velocity;2)T he body angle of athletes at the moment of touch-down in triple jump are 90.33±4.17°,90.81±3.25°,81.49±8.39° respectively,and the moment of take-off are 87.61±4.19°,84.99±3.20°,82.44±4.40°.In the take-off stage of the triple jump,athletes basically ke ep their torso upright or moderately forward,which is conducive to quick cushionin g and taking off;3)The knee angle of athletes’ support leg at the moment of touchdown in triple jump are 148.05±5.58°,153.78±5.61°,151.13±6.44° respectively.Athletes generally use the small knee angle touchdown technique,buffer amplitude is small(11.99±5.87°;19.20±8.23°;19.14±8.72°).Knee joint of support leg appear “bending” m ode at the moment of take off;4)The angular velocity of the swinging leg at the m oment of touchdown(7.31±2.23rad/s;5.53±1.58rad/s;5.12±1.39rad/s)and the maximu m angular velocity of swinging leg(14.36±1.44rad/s;11.98±1.39rad/s;11.55±1.03rad/s)on the triple jump is relatively small.The fast swing ability of the swing leg is rela tively poor;5)The hybrid arm swing technique is commonly used by athletes;6)The l oss rate of horizontal velocity in the triple jump of athletes is small(8.70±2.47%;12.43±1.81%;15.44±2.84%),and the vertical velocity at the moment of take off on ste p and jump is small(1.79±0.28m/s;2.41±0.28m/s),which leads to the small take-off angle(12.51±2.10°;19.48±2.85°).Conclusions:(1)The athletes need to strengthen the pre-swing of the swing leg before touchdown in the triple jump and the fast swing ability of the swing leg in the take-off stage.The fast swing of the swinging leg can increase the athlete’s touchdown angle and promote the athlete’s center of gravity to move forward quickly,so as to reduce the loss of horizontal velocity;2)The technique of touchdown with smaller knee angle is generally adopted by the athletes,which is beneficial to the positive downward press and back swing of the shank,and the knee joint can reach the best range of pushing and extending the knee angle with a small cushion.However,at the moment of take off,the support leg appears obvious "bending" mode,and the push extension is not sufficient.Therefore,the fast push extension ability of lower limbs should be further strengthened;3)The athletes have strong ability to maintain horizontal velocity,but the vertical velocity and take-off Angle are small at the moment of take off in step and jump,which affects the distance of triple jump and can further promote the conversion from horizontal velocity to vertical velocity;4)Based on the kinematics analysis of the technique of the athletes,construct the technical evaluation and scoring model of Chinese elite men triple jump athletes.