| Research objective: This paper selects Song Jiayuan’s six main competitions in 2021 as the research object.Through the kinematic diagnosis and evaluation of Song Jiayuan’s rotating shot put technology,the key factors affecting Song Jiayuan’s technical characteristics are summarized according to the data,and the biomechanical parameters of foreign excellent female shot put athletes are compared.The deficiencies of Song Jiayuan’s rotating shot put technology are found out according to the characteristics of each stage of the movement,providing reference for the coaches to develop scientific training in line with Song Jiayuan’s personal characteristics,To provide theoretical basis and practical reference value for improving Song Jiayuan’s rotating shot put technology.Research methods: This paper adopts the methods of literature,experiment and mathematical statistics.The experimental method uses two JVC GC-PX100high-definition cameras to shoot Song Jiayuan’s throwing technical movements.The analysis software selects APAS 3D motion analysis system and Fastmove Motion-3D Sharp 3D analysis software from ARIEL Company of the United States to analyze the kinematics of the video.Use Excel(2022)table to sort out the data tested,classify and count the data according to the different parameter categories selected,and use SPSS26.0 statistical software to establish a database for the collected data.Use Pearson correlation analysis method to carry out statistical analysis on each group of data,and judge the correlation between each parameter and the final score and between each parameter according to the correlation comparison.Research results:1.The average time of Song Jiayuan’s first single support stage is 0.47 ± 0.01s;The average time of the spinning phase is 0.10 ± 0.01;The average time of the second single support stage is 0.20 ± 0.01s;The average time of the final force stage is 0.20 ±0.13s;The average total time of rotation is 0.98 ± 0.01 s.2.The average speed of Song Jiayuan’s shot put was 2.04 ± 0.07m/s and the average speed of the center of gravity was 0.73 ± 0.10m/s at the moment when her right foot was off the ground;The average speed of shot put at the instant of shot put is 11.84 ±0.36m/s,and the average speed of center of gravity is 0.92 ± 0.08m/s.3.The average speed of Song Jiayuan’s left shoulder at the moment of landing was4.35 ± 0.34m/s,and the average speed of her right shoulder was 2.30 ± 0.31m/s;The average speed of the left shoulder at the instant of shot put is 3.43 ± 0.27m/s,and the average speed of the right shoulder is 4.73 ± 0.43m/s.The average speed of the left hip at the moment when the right foot is off the ground is 0.80 ± 0.05m/s;The average speed of the left ankle at the moment of landing of the left foot is 3.44 ± 0.25m/s,and the average speed of the right ankle is 1.59 ± 0.23m/s;The average speed of the left ankle at the instant of shot put is 2.51 ± 0.20m/s,and the average speed of the right ankle is 4.60 ± 0.31m/s.4.The average left shoulder angle at the moment when Song Jiayuan left her right foot off the ground was 86 ± 4.74 °,and the average right shoulder angle was 76 ± 4.41 °;The average left shoulder angle at the moment of shot put is 103 ± 4.92 °,and the average right shoulder angle is 105 ± 4.10 °.The average left hip angle at the moment when the left foot is off the ground is 122 ± 5.97 °,and the average right hip angle is148 ± 7.75 °;The average left hip angle at the moment of landing of the left foot is154 ± 6.41 °,and the average right hip angle is 165 ± 3.67 °;The average angle of the left ankle at the moment of shot put is 130 ± 6.11 °,and the average angle of the right ankle is 112 ± 10.68 °.5.Song Jiayuan’s average trajectory of shot put during the spinning stage is 0.12 ±0.01 m,and the average trajectory of center of gravity during this stage is 0.23 ±0.02m;The average trajectory of shot put in the final force stage is 1.43 ± 0.04 m,and the average trajectory of center of gravity in this stage is 0.31 ± 0.03 m.6.Song Jiayuan’s average overall shot put speed is 11.84 ± 0.36m/s,the average shot put angle is 40.3 ± 2.69 °,and the average shot put height is 2.02 ± 0.02 m.Research conclusion:1.Song Jiayuan spent more time in the first single support stage during the whole spinning throwing process;In the final stage of exertion,there was also a problem of more time,and Song Jiayuan’s time allocation for six throws was unreasonable.2.Song Jiayuan’s shot put speed was significantly faster at the moment when her right foot was off the ground.Song Jiayuan deliberately accelerated the equipment in advance at the initial moment of the first single support stage,which made the shot put control unstable at this stage;The shot put speed of the right foot dropped sharply at the moment of landing,and the body posture could not be controlled stably;There was no obvious phenomenon of "delaying the speed of the instrument" in the shot put when the left foot landed.The overall speed fluctuates greatly,and the shot put control is unstable,especially when the right foot lands.3.Song Jiayuan’s left and right shoulder speed changes significantly in the first single support stage,and the upper body control is unstable during rotation;In the second single support stage,at the moment of landing of the left foot,the left ankle speed decreased slightly,which was not conducive to the stability of the left side as the support axis at this time;The left hip joint accelerated ahead of time before shot put.4.Song Jiayuan’s right shoulder angle declined during the take-off and rotation phase,and the small left shoulder angle made the left arm(auxiliary arm)and hip in a poor state of tightening,without good stretching of the left muscle group;At the end of the second single support stage,Song Jiayuan’s right hip angle increased slightly,and the left lower limb had a large angle at the knee joint.At this time,the right foot was not obviously pressed under the ground,the center of gravity was high,and the lower limb compression effect was not good;At the final stage of exertion,the pedal and extension of the lower limbs are not sufficient,and the angle of the knee and ankle joint is too large,which can not exert the strong pedal and extension function of the lower limb extensor muscle group.5.Song Jiayuan had a low total distance of the shot put track during the rotation process.The center of gravity track in the second single support stage fluctuated the most.The other three technical stages were relatively flat,and there was no large ups and downs.6.The key problems of Song Jiayuan’s shot put instant in the final force stage are that the shot put speed is too small,the shot put angle is large and the control is unstable,and the shot put height increment is small. |
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