Sports Biomechanical Analysis Of Snatching Movement Techniques Of Key Players In Shaanxi Women’s Weightlifting Team

Research purpose: Shaanxi Province women’s weightlifting team has developed rapidly,experienced from scratch,from there to strong,and has completed the echelon construction,newcomers emerged,in recent years in the national competition frequently break through the best results.However,several key players of Shaanxi women’s weightlifting team have weak grip problem,which has become a stumbling block to prevent Shaanxi women’s weightlifting team from climbing to a higher peak.Therefore,this study will analyze the kinematics and kinetics of several key members of Shaanxi women’s weightlifting team,and analyze the characteristics of the current weightlifting technique of key members of Shaanxi women’s weightlifting team from the perspective of sports biomechanics,in order to provide a theoretical reference for the development of Shaanxi women’s weightlifting team and contribute to the development of Shaanxi sports.Research method: This study mainly used literature method,expert interview method,three-dimensional fixed-point camera measurement method,three-dimensional dynamometer test method,and mathematical and statistical method.Two high-speed cameras and a three-dimensional force measurement system produced by Swiss kistler company were used to conduct three-dimensional photography and three-dimensional force measurement bench tests on the snatching movements of Xiang Qiu Xiang,Long Xue and Wu Xiaofeng,and the complete video of the snatching movements was analyzed using the German Simi Motion 9.2.2 motion video analysis system for joint punctuation and The kinematic analysis was performed using Matlab software for time normalization;the measured kinetic data were organized and calculated using Excel,and the kinetic data were weight normalized,and the resulting data were finally plotted and analyzed using Graph Pad Prism 9.0.0 and Origin 2019 software.The kinematic indexes selected in this study were grip distance;standing distance;hip and knee joint trends over time;distance between body center of gravity and barbell center of gravity on the X-axis（front and back）;body center of gravity and barbell center of gravity vertical velocity trends over time;trajectory of body center of gravity and barbell center of gravity;time ratio of each phase of the grip process and barbell vertical rise height ratio.The kinetics was analyzed mainly for the ground reaction forces in the front-toback,left-to-right and vertical directions.The results:（1）In the preparation phase,the grip distance and the standing distance of Long Xue were both maximum,but the larger standing distance would weaken the strength of the leg extension muscles during the snatch and lift to a certain extent and could not achieve the maximum strength.（2）Xiang Qiu Xiang’s hip joint increased the maximum in the second power phase,which made full use of the power of the hip joint and was conducive to increasing the vertical speed of the barbell.（3）The trend of knee joint angle changes over time was basically the same for all three people,showing the form of "double peak and single valley",but the knee flexion angle was generally smaller for all three people in the knee pulling phase.（4）Long Xue’s bicentric distance is much larger than Xiang Qiu Xiang and Wu Xiaofeng,too large bicentric distance will destroy the balance and increase the chance of failure.（5）The analysis of the time spent in each phase of the snatch and the percentage of the vertical height of the barbell can be found that there is still some room for improvement in the snatch performance of Xiang Qiu Xiang and Long Xue.（6）In the front-to-back direction,the front-to-back sway of Long Xue was significantly larger than that of Xiang Qiuxiang and Wu Xiaofeng.In the left and right direction,the left and right sway of Xiang Qiu Xiang and Long Xue was larger,while Wu Xiaofeng’s left and right offset was smaller and relatively more stable.In the vertical direction,the S value of Long Xue was much larger than that of Xiang Qiu Xiang and Wu Xiaofeng,showing a stronger stirrup burst ability.Conclusion:（1）Xiang Qiu Xiang’s snatch technique is more mature than Long Xue and Wu Xiaofeng,but the explosive power of the legs is lacking,and the training of explosive power of the legs needs to be strengthened.（2）Long Xue’s leg explosive power is the largest among the three,but the core stability is weak,easy to appear front and back and left and right direction of the sway,and Long Xue in the snatch process of the two heart distance is larger,easy to destroy the balance,increasing the chance of failure.（3）Wu Xiaofeng is younger,the explosive power of the legs is lacking,there is still more room for growth.