Three-dimensional Kinematic Analysis Of Take-off Techniques Of Some Outstanding Male Long Jumpers In Tianji

Using the method of literature,expert interview,three-dimensional video analysis and mathematical statistics,this paper takes the take-off techniques of 6athletes in the long jump final of the Tianjin Section of the National Track and Field Special Competition in May 2022 as the research object.By shooting the competition video,using KNOW3 D software to punctuate the data of each moment and each stage,compared with the domestic elite athletes,find out the technical characteristics of the six Tianjin long jumpers,find out the advantages and disadvantages of the six long jumpers,and put forward the corresponding improvement training methods.It is hoped that the final research results of this paper will help Tianjin male long jumpers improve their take-off techniques.The results show that:1.At the moment of take-off and landing,the hip joint technique of the six long jumpers in Tianjin was reasonable.The knee Angle of 6 athletes’ jumping legs was less than the ideal Angle,and the active pedal was not active enough.The Angle between the thighs of the 6 athletes is smaller than that of the domestic elite athletes.The 6 athletes in Tianjin have faster leg swing speed and active forward body center of gravity.Athletes Wang *,Zhang **,Zhang ** is better than the other three athletes in the swing technique.The horizontal speed and vertical speed of the body center of gravity of 6 athletes were lower than that of the domestic elite athletes.2.Maximum buffering moment,the side of the take-off leg of 6 Tianjin long jumpers basically conforms to the action characteristics of this stage.The average knee joint of the 6 athletes’ jumping legs was in line with the ideal Angle range,and the Angle of the hip joint and knee joint of the 6 athletes was basically the same as that of the domestic elite athletes.The Angle between the thighs of Wang *,Zhang ** and Zhang** was smaller than that of the other three athletes.The horizontal speed of the athletes on one side of the jumping leg is basically the same,but the vertical speed varies greatly.The horizontal speed and vertical speed of the 6 athletes are lower than that of the domestic elite athletes.3.At the moment of take-off from the ground,the hip Angle of the six long jumpers in Tianjin was less than that of the domestic elite athletes,and the hip joint of the Tianjin athletes was not fully extended.The kick off Angle of 6 athletes is less than the ideal kick off Angle.The knee joint and ankle joint technique of 6 athletes were reasonable.The overall difference of the knee Angle of the 6 athletes’ swinging legs was great,and the Angle between the two thighs was basically the same as that of the domestic elite athletes.The speed of the center of gravity level of 6 athletes was lower than that of the domestic elite athletes.The vertical speed of the center of gravity of 6 athletes is higher than that of the domestic elite athletes.4.During the landing cushion stage,the hip,knee and ankle joints of the six long jumpers in Tianjin basically met the technical requirements of the landing stage.The variation of hip joint and ankle joint of Tianjin long jumpers is less than that of domestic and foreign elite athletes.All the joints(except the knee joint)on one side of the swinging leg of the 6 athletes basically conform to the movement characteristics at this stage.The jumping time of the 6 athletes is basically the same as that of the domestic elite athletes,but the jumping time of athlete Yang ** in this stage is longer than that of the domestic elite athletes.The body displacement of the 6 athletes was different in this stage.5.In the stage of take-off and push and stretch,6 long jumpers in Tianjin had hip flexion without active push and stretch.Tianjin long jumpers Wang * and Zhang **showed greater changes in the Angle between their legs and better range of leg swings than the other four athletes.The 6 athletes had poor motivation to actively swing their knee joints upward.The take-off time of the 6 athletes is basically the same as that of the domestic elite athletes.There is no significant difference between the horizontal displacement and vertical displacement of the body center of gravity.6.The average horizontal speed loss rate of the 6 athletes in Tianjin was in line with the normal range,but the overall difference was large.The loss rate of athletes Zhang** and Wang ** is greater than the overall average,indicating that the buffer time of athletes is longer,and the loss of horizontal speed affects the performance of the competition.Yang’s loss rate was low,indicating that the athlete did not fully push out and take off too quickly.