Research On The Technical Characteristics Of Throwing Step And Final Force Of Javelin Athletes In Hebei Province

The javelin throwing movement is a throwing project completed by a series of complicated technical actions such as holding a gun,throwing a gun,and finally throwing a gun.This paper takes the characteristics of the throwing step technique and the final exertion technique of the javelin throwers in Hebei Province as the research object.The main research body is the javelin throwers in Hebei Province,including 4 male javelin throwers(Long Zexuan,Jiang Pan,Wang Mingyuan,Wu Sen)and 3 women athletes.(Ge Lijuan,Du Simeng,Dou Koulin).The research of the throwing stage is divided into four aspects,namely step size feature,step time feature,speed feature and body posture feature.Finally,the force phase is divided into four aspects,namely action time feature,speed feature,body posture feature and Javelin shot initial condition characteristics.This article is based on the Hebei Provincial University Athletics Training Center,the Hebei Provincial Athletics Management Center,and the National Excellent Javelin Athletes Group Competition held in Tianjin Tuanbo Sports Center on June 1,2018,at the Hebei Provincial Sports Center on May 20,2018.The object,using two high-speed cameras for simultaneous shooting,the best score of the seven athletes in six throws during video analysis,using SIMI Motion three-dimensional motion analysis system for the seven athletes in the throwing stage and the last stage of the javelin The analysis of sports technology,combined with the literature data method,expert interview method,comparative analysis method and mathematical statistics method,to study the throwing step technique and final force technical characteristics of the javelin throwers of Hebei Province track and field team,and compare the corresponding techniques of Chinese excellent javelin throwers Characteristics,in order to find out the problems of the Hebei Javelin team,improve sports performance and provide reference for future training and teaching.Through the analysis of the movement of the seven athletes throwing javelin technology,the following conclusions are drawn:The technique of throwing and final exertion of the javelin throwers in Hebei Province has obvious characteristics.Unlike the average level of domestic elite athletes,the Hebei team's throwing stage shows the characteristics of small stride and fast pace;while the final exertion stage is due to the protruding speed.Sacrificing the characteristics of the action amplitude,the specific characteristics of the two phases are as follows.(1)Technical characteristics of the throwing stage of the javelin throwers in Hebei ProvinceStep size characteristics: the first three steps are smaller(small 10-19cm),the fourth and fifth steps are larger(larger 5-13cm),and the last step is the smallest(small 14cm),presenting The characteristics of small step size and fast pace.Such a step size distribution method is beneficial to speed up the step frequency,but reduces the force range of the human body and the device.Step characteristics: the first two steps(length 0.008-0.073s),the third step short(short 0.008s),the last three steps longer(length 0.029-0.063s),showing a small step size,step length Characteristics.Among them,the characteristics of the woman are: the first three steps,the last two steps are longer,and the last step is shorter;the men are: the first two steps,the third step is short,and the last three steps are.Although this step-time feature is beneficial to speed up the movement of the lower limbs,it sacrifices the force of the human body and the instrument,which is not conducive to the final exertion.The speed characteristics are: horizontal running speed: the first four steps are slow(slow 0.3-0.4m/s),and the last two steps are slower(slower 0.3-0.5m/s,showing a slower horizontal running speed and a lower loss rate)High characteristics.Therefore,the speed loss rate is high,and the horizontal momentum obtained by the human body and the instrument is low;the speed characteristics of the right hip during the cross step are: fast(0.2m/s),slow(0.1m/s),slow(0.3 m/s),showing the characteristics of uncoordinated lower limb paralysis.Among them,the characteristics of men are: fast,fastest,faster;women's characteristics are: fastest,fast,faster.It is beneficial to speed up the movement of lower limbs,increase the body and The force of the device.Body posture characteristics: The pull angle is: the throwing arm is full of guns,which is beneficial to the control and final exertion of the throwing arm to the gun;the back tilt angle of the trunk: the first two steps are too large(5.9°-8°)The latter two steps are small(small 2.7°-4.7°),and the fifth step is the smallest(small 11.3°).It shows the characteristics that the trunk has a small backward tilt and a fast step frequency.It is not conducive to the full formation of the attitude beyond the instrument,the torsion force is small,and the speed loss rate is high.The angle between the shoulder axis and the throwing direction: the first three steps are small(small 6.4°-9.6°),and the last two steps are small(small 0°-4.5°).Among them,the characteristics of men are: the first two steps are small and the last three steps are small;the women's characteristics are: the first two steps are small and the last three steps are large.It is beneficial to the throwing arm to achieve the charging gun and to increase the torsion of the shoulder shaft and the hip shaft.The angle between the hip axis and the throwing direction: the first four steps are larger(larger 0.5°-20.8°)and the fifth step is larger(larger 25.1°).Among them,the characteristics of men are: the first two steps are too small,the last three steps are too large;the characteristics of women are: the first three steps are too large,and the last three steps are too small.It is conducive to the maintenance of the horizontal running speed and the final force.(2)Technical characteristics of the final stage of the javelin throwers in Hebei ProvinceAction time characteristics: The last action time shows the characteristics of “full bow” with a long duration(0.041 s slow),a slow “whipping” speed(0.020 s slow),and a long action time(0.061 s slow).The final effect is poor,which is not conducive to the rapid shooting of the javelin.The right side of the torso is characterized by a high speed on the right side of the torso.Advantageously and beyond the formation of the instrument posture increases the magnitude of the torso force.Speed characteristics: The horizontal running speed characteristics are: slow when the right foot touches the ground(slow 0.7 m/s),slower when the left foot touches the ground(1.1 m/s slow)and high speed loss rate(7.7% higher)feature.The left leg brakes slowly(0.2m/s slow)and the support effect is poor,which is not conducive to the rapid force on the right side of the trunk and the quick “whipping” of the trunk;the right side of the torso shows: the right side of the trunk moves toward the throwing direction.The speed is slow and the torso of the torso is slow.The speed and amplitude of the force when the torso is "whipped" is reduced,which affects the flying distance of the javelin.Body posture characteristics: The trunk recoil angle is characterized by a small backlash(17.3°-18.6°)and a small torso angle(25°).It is beneficial to reduce the braking of the horizontal direction and the speed of the running speed,but the force of the human body and the instrument is small;the bending angle of the left knee shows: the bending angle is small(small 14.9 °-52.4 °),the cushioning degree and the heeling degree are compared.High(28.6°,37° high)and long stretch time(length 0.007s).Conducive to the rapid braking of the left leg,but the "rigid" support is insufficient;the right knee bending angle shows: the right knee bending angle is small(small 14.2 °-19.2 °),the stretching time is longer(slow 0.098s)characteristics It is beneficial to the rapid transition of people's weight,but affects the rapid force on the right side.When the "full bow" is formed,the throwing arm pulls a large angle(91.1°),which is beneficial to increase the working distance between the human body and the javelin.Initial conditions of the javelin shot: The speed of the javelin shot is 21.3m/s,the speed of the shot is slow,and the speed of the javelin is low;the angle of the javelin shot is 33.6°,which is close to the best throw angle,but the speed of the shot is slow.The flight is low;the initial angle of attack of the javelin is-4°,the initial angle of attack is low,the angle of attack after the javelin is shot is small,and the flight is low.