Kinematics Characteristics Of The Joint Techniques Of Run-up And Take-off In The Last 5m Of Chinese Elite Male Long Jumpers

With the continuous improvement of the level of track and field sports,track and field sports performance is also in a relatively stable stage of development,the key technologies of each project and the qualitative and quantitative analysis of the project are more accurate.The joint technology of run-up and take-off in long jump is a link between the preceding and the following in the whole long jump process,which is undoubtedly the key link of long jump technology.Taking the kinematics characteristics of the last 5-meter run-up and take-off joining technique of Chinese Elite Male Long Jumpers as the research object,this paper investigates the top 8 male long jumpers who participated in the 2018 National Track and Field Championship.The kinematics parameters of the last 5-meter run-up and take-off joining technique of long jump are collected mainly by using video shooting method and Dartfish software analysis method.Through the methods of documentation and mathematical statistics,the data are sorted out and analyzed,and the following conclusions are drawn:(1)The change characteristics of step length in the last 5-meter run-up stage of 8subjects were as follows: the step length in the first step was less than the step length in the second step,and the change rhythm of step length was ideal,but the step length in the second step and the step length in the second step were significantly smaller than that of the excellent athletes at home and abroad,and the T test results were very significant different.(2)The speed change characteristics of 8 subjects in the last 5-minute run-upstage were as follows: Five of them had faster speed change before takeoff,but the speed difference between before and after takeoff was large,and the run-up rhythm changed abruptly.In addition,the run-up speed is also significantly lower than that of domestic and foreign elite athletes.(3)The average values of landing angle and kick-off angle of 8 participants in the take-off stage are significantly lower than those of the world's elite athletes,and the average values of the sector angle of take-off are much larger than those of the world's elite athletes.The trend of the change of the hip joint angle of the take-off leg is not consistent with that of the world's elite athletes.(4)The horizontal take-off speed of 8 subjects is relatively small,but the difference is not large.The vertical take-off speed is significantly lower than that of domestic and foreign elite athletes,and there is a very significant difference with the T test results of domestic and foreign elite athletes.In addition,the time allocation of the eight subjects in the take-off stage is unreasonable,and the buffer time in the take-off stage is longer,which results in the total take-off time significantly longer than that of the elite athletes at home and abroad.(5)The accuracy of pedals of the eight men's long jumpers who participated in the final of the 2018 National Track and Field Championship is also relatively unsatisfactory,which reflects that the approach rhythm of Chinese men's long jumpers is not stable at this stage.