A Comparative Study Of Kinematics Of Run-up And Take-off Techniques Of Different Level Long Jumpers

Research purposes: In recent years,China's long jump project has made rapid progress,especially for men's long jump.Many athletes have repeatedly created top 8or even top 3 scores in the World Championships and the Olympic Games.In order to compare the different technical performances of the long-distance athletes in the run-up and take-off stages of different ages,distinguish the skill types of athletes,deepen the understanding of the long jump project,provide some reference and basis for the athletes and coaches who work in the long jump project,and also for China.The selection of long jump athletes and the development of the reserve talent team for the long jump project will provide some help.Research methods and objects: the 2017 National Track and Field Individual Reserve Talent Base Championships(14-17 years old)and the 2018 National Youth Athletics Championships(18-19)through the methods of literature,two-dimensional filming,video analysis and mathematical statistics.In the men's and women's long jump finals of the 13 th National Games in 2017,the last 6 athletes' run-up last 6 steps,the last 6 steps of the run-up,the speed loss rate before and after the jump,and the angle of the jump.Analyze and study the different technical performances of each link.The results of the study:(1)The overall performance of the male and female children is: the final 6-step average step size,the final 6-step running average speed and the pre-board horizontal speed have a significant positive correlation with the competition results,the relevant men are(r=0.542,P< 0.01,r=667,P<0.01,r=0.761,P<0.01),women were(r=0.600,P<0.01,r=828,P<0.01,r=0.673,P<0.01);take-off time Significantly negatively correlated with the results of the game(men: r=-0.840,P<0.01,women: r=-0.575,P<0.01);the vertical speed and the angle of the jump fromthe board are not related to the game results;In addition to the male athletes,each of the remaining 46 male and female athletes has an obvious asymmetry of left and right step lengths in each of the last 6 steps of the running,and the performance is that the step of jumping legs is larger than that of non-jumping legs.(2)Pairwise comparison between men and women of three different age groups: higher exercise level showed better landing moment,two thigh angles,last 6 steps of support support vacancy time ratio,and last 6 steps of running length variation coefficient Etc.,and the difference between these indicators and the lower level group was statistically significant(P <0.05).(3)There was no significant difference in height between the two groups(P>0.05),but the height of the higher group in the three groups was higher,and the differences between the three groups were statistically significant.Academic significance(P<0.05).Research conclusions:(1)The technical level of running between different horizontal athletes of the same gender directly affects the speed of running.The high-level athletes run shorter,the supporting process time is shorter,and the two legs exchange speed is faster during the vacating process.Fast,the pressure on the legs is more positive.(2)The final 6-step running of athletes of different levels has different degrees of asymmetry of left and right leg steps.The higher the level of the three groups of the same gender,the more stable the rhythm of the last 6 steps of the group.(3)Women generally develop earlier than men,which may be the reason why the step size and speed potential of women's athletes do not increase much with age.In the long-term selection of young people,it is necessary to pay attention to the development potential of male and female athletes of different ages.different.(4)The higher the same gender level,the group did not show a larger angle of take-off.The take-off technique should be evaluated from multiple dimensions such as take-off time,take-off fan angle and take-off speed loss rate.