Kinematic Analysis Of Final Run Up And Final Effort Technique Of Chinese Elite Female Javelin Athletes

Objective:using the high speed camera of eight female athletes before and after the run up stage of javelin last exertion action techniques for uninterrupted shooting from the kinematic analysis from the perspective of the two key stages of research and analysis,and obtain their relevant kinematic parameters in the run up and the late delivery stage,and according to the different parameters reflect the athletes to point to analysis,to clarify technical characteristics of our elite female javelin athletes.Based on the related technical theory to explore the characteristics of individual athletes from technology and throwing effect between;at the same time in the process of analysis of some parameters and related indicators,such as:the athletes in the countdown to the second step in the ankle and knee joint before and after contrast,cross step body displacement of the horizontal speed loss value,too little analysis in previous studies,but this impact on the final performance factors can not be ignored,so as to provide some new ideas to improve the athletes technology.At the same time,from the formation of a reasonable and effective technical level,a theoretical data basis is provided so that the overall level of the women's javelin project in china has been continuously developed.Research methods:This paper mainly through the methods of experimental research,study the top eight female javelin throw athletes in the 2017 national track and field throwing group competition(xi pu,si chuan).They strobe-photographed the athletes'javelin throw process during the competition,choosing the data of the last SIX throw for each of the top eight athletes in the finals,totaling 48 throw as study dataset.They used DARTFFISH sports photo analysis software,reviewed the technical processes particularly focusing on the vital part of the later run-up and final throw of the top eight female javelin throw athletes,acquired relevant reference numbers like the javelins' speed just at release,the important angles such as the last step left leg supporting angle and the right leg's curving angle,along with other kinematics parameters such as speed and distance.The results of the study:1.Fourth step back the eight athletes run and third step back,step height ratio was lower than that of the standard in addition to Hanes Lu will be in the third steps higher than average Hanes standard.Average step length used respectively for 0.29s and 1.44m,the difference between the average pace of the elite athletes of the world is 0.23and 0.24m.2.Step 2.Liu Shiying throwing in the penultimate step forward motion of the knee and ankle tends to smooth,make the right leg rapid formation of "cross swinging forward" movement,prompted the body lower limbs form the attitude that"throw" forward actively.While the knee and ankle movement of Zhu Dandan,there are obvious uplift,the right leg of some knee-bending movements.3.When forming the left side of the support,the athletes after the torso Angle is not in the scope of reasonable only ling wei,Yang Xinli and Su Lingdan after the three athletes and their torso Angle of only 17.6 ° and 17.3 ° and 17.3 °.4.The performance of the best Liu Shiying levels before they move speed 24.8 m/s,maximum horizontal movement speed after they fell to 20.96 m/s,horizontal speed loss value reduced 3.84 meters/seconds.However,the horizontal movement speed of zhu dandan and Su lingdan in the middle and lower grades of the grade was increased by 3.16 and 3.04 m/s.5.Reasonable to high coefficient of the foreign excellent athletes "0.89",our country athletes Yang Xinli,Zhudandan,Ren Qing zhuoma three shots,height coefficient were 0.86,0.83,0.85,less than a reasonable height coefficient.6.Li Linwei and Yang Xinli shoot Angle is too large,the two athletes is higher than the world average will be about 2°,javelin to Angle is too big,to a certain extent affect the speed of the athletes shoot.Also,Zhu Dandan is too small,will also affect the speed.7.Through comparing to speed data,except Liu Shiying,Lu Huihui and Ren Qing zhuoma the three athletes can comparable with the world's best players to speed,the remaining five female athletes in the javelin to speed compared with the best athletes in the world still exists a certain gap.The conclusions of the kinetic analysis are as follows:1.The run up speed of the last four steps of the top eight athletes in the national track in 2017 did not show its proper advantage,the average speed of each step is lower than the average speed of every runner in the world's elite runners,and it can't fully satisfy the general rule of throwing steps of the world excellent javelin throwers.The eight elite athletes in our country have relatively short step length and relatively short running time,especially in the fourth steps of the throw step.2.The study found that among the eight the athletes in most athletes at the second step,there by shortening stride shortening phenomenon,show that the athletes declined relatively obvious speed,indicating that these athletes body and some joint support ability is limited,into the emergence phase of the left leg support,the consciousness of self protection the state of decline low displacement speed.3.Zhu Dandan's knee and ankle trajectory showed more obvious upward projections,which demonstrates that the process of the athletes in throwing step second last step in the emergence of the swing leg has obvious high knee action.4.The left side support moment,the relative position between the human body and equipment and support points,the kinematic parameters of the Liu Shiying,representing the basic characteristics of elite female javelin athletes of our country,embodies the javelin movement structure reasonable,but other athletes in some details still exist deficiencies,shortly working distance and hold point to the left foot to support a short distance,lead to it doesn't fully extend their upper limbs.5.YangXinli?ZhuDandan and RenQin dolma three people shot height coefficient is too low,resulting in reduced body weight premature,bending amplitude of the body is too large.This not only reduces the javelin angle,also destroyed the motion rhythm last strength and reducing the release speed.