A Study On The Throwing Step And Final Exertion Technique Of The Elite Female Javelin Throwers In My Country

Javelin throw is a technically complex field race project that is based on strength,speed as the core,and speed and strength combined with a sport.In many years of practice and research,people have divided the complete javelin throwing technology into five action technical stages: holding gun,running,final force,body balance after the javelin shot and flight of the instrument.The two stages of running and final exertion play a vital role in throwing results.This paper uses the literature method,mathematical statistics method and video analysis method to measure the step length,step time,speed utilization rate of the female javelin thrower in the 2017 National Track and Field Championship,and the left support technique and the throwing arm force in the final exertion stage.The relevant parameters such as sequence and instrument release status were studied,and compared with the relevant parameters of eight outstanding athletes in the world,the following conclusions were drawn:1.Compared with the world’s top athletes,the Chinese athletes have shorter strides and slower speeds in the four strides after the throwing stride,especially the two strides of the throwing stride(impulse stride).The height of the center of gravity is too large,which affects the speed of the running.It is not conducive to the initial kinetic energy acquisition in the final exertion phase;the first stride of the delivery stride,the left foot is not active on the ground,and the stable double support phase is not formed in time.2.In the stage of throwing,the back tilt angle of the torso of the Chinese athletes in 4steps and 3 steps is more reasonable.The back angle of the torso of the 2 steps and the 1 step is smaller,which is not conducive to the formation of the instrument.The two-step(cross-step)movement of athletes in China is small,which limits the increase of the back-tilt angle of the3~2 steps,which is an important reason for the small inclination of the torso after 2 steps and1 step.3.Compared with the world’s top athletes,the left-leg support of the Chinese athletes is larger,and the initial state of the left support is good.However,due to the poor support ability of the left leg,the change of the left knee angle after the ground is too large.It is not conducive to the transmission of kinetic energy from the bottom up.4.In the final stage of exertion,there is no significant difference between the strength of the athlete’s torso in China and the world’s elite athletes.However,by comparing the trajectory of the athlete’s wrist joint and the distance from the projection point to the left footsupport point,the actual working distance of the Chinese athletes on the instrument is found.Shorter,the javelin shot too early,affecting the effectiveness of the "whipping" action.5.The angle of the handgun,the attitude angle and the attack angle of the Chinese athletes are more reasonable.The direction of the force is closer to the longitudinal axis of the javelin,but the speed of the instrument is slower,which affects the actual flight distance of the javelin.