Kinematics Analysis Of Starting Technique For 500m Short Track Speed Skaters

The starting technique of short track speed skating has an important influence on the performance of athletes,especially on the 500 m race in which the starting action and starting technique can determine the final ranking of the race.Therefore,most short track speed skaters will try their best to improve their ranking and performance by wearing high-tech speed skating clothes and skates.However,compared with the influence of external equipment,short track speed skaters' body tilt angle,body explosive force,body movement attitude and so on have a greater impact on their final performance.This study mainly focuses on the study of young short track speed skaters,and analyzes the important factors influencing the performance of short track speed skaters,such as body tilt angle,starting action,center of gravity displacement,etc.Under the guidance of the research goal of the starting technique of short track speed skating,6 athletes of different levels(2 athletes of master level,2 athletes of first level and 2 athletes of ordinary level)in Mudanjiang athletic sports school are chosen as the research objects,and various research methods such as literature,photogrammetry,video analysis and mathematical statistics are used to collect and analyze the skaters' body elements in the stage of preparation,starting and sprint of short track speed skating.In the three-dimensional fixed-point camera method two high-speed cameras are used to shoot the front and side sliding posture of athletes,including the athletes' body posture and biological joint coordination under different time nodes,such as static state,starting and pedaling state,sprint and acceleration state,based on which the statistics and analysis are made on the data of athletes' body posture and biological joint coordination to obtain the kinematics research results of the athlete's step frequency,stride and lower limb joint in the whole starting stage.The results are as follows:(1)In the preparatory stage,the angle of the knee and hip joint of the front supporting leg of the elite athletes and the first-class athletes is smaller than that of the ordinary athletes.The excessive angle of the front knee and hip joint makes the height of the center of gravity higher and the angle of the upper limb forward tilt larger,whichleads to the big air resistance and the long starting time in the next movement stage.The angle of the knee and hip joint of the elite athletes and the first-class athletes is larger than that of the ordinary athletes.The larger the angle of the knee and hip joint is,the smaller the angle of pedaling is,the higher the horizontal speed is.Therefore,in the preparatory stage,the small angle of the front knee and hip joint and the large angle of the rear knee joint are more favorable for the starting stage.(2)In the starting stage,the starting time of ordinary athletes is relatively longer and the speed is comparatively lower in comparison with the first-class athletes and elite athletes.In the process of pedaling,the angle and angular velocity of the knee joint of the elite athletes and the first-class athletes are 64 °-70 ° and 400 ° / s at the moment of pedaling away from the ice surface,which indicates that the muscle of the knee joint of the elite athletes and the first-class athletes shows strong stretching ability and explosive force,so the stronger the leg muscle is,the greater the explosive force is,the more conducive to the increase of speed and the decrease of time in the pedaling stage.(3)In the stage of sprint,the elite athletes and the first-class athletes have longer stride length and higher stride frequency than the ordinary athletes,and the difference is bigger in the stride frequency.Although the stride length of the ordinary athletes is about 0.15m-0.24 m shorter than that of the elite athletes and the first-class athletes,the stride frequency is lower,resulting in lower speed and longer time.And from the first step to the third step,the horizontal speed of the athletes increases rapidly and the vertical speed changes relatively steadily,which shows that the main purpose of the acceleration process of sprint is to increase the horizontal speed,reduce or maintain the vertical speed.It is hoped that the research results can provide theoretical and data reference for the scientific training of coaches,and help coaches to guide athletes to carry out scientific training,so as to improve the standard of training and the performance of athletes.