| Objective: Horizontal bar riding front loop is rotating axis in the middle,the above body and two legs formed three force moment and the formation of the bar loop action,is the sports colleges gymnastics class content and military training gymnastics program must master the basic action,the action of vestibular organs,upper limb strength,shoulder muscle strength,body coordination,cultivate brave and decisive good quality has special effect,but the action is high technical requirements,breathtaking,teaching effect is not ideal,and easy to damage.This study by comparing different levels of athletes to complete the kinematics index and surface EMG index,the kinematics index,surface EMG index,technical characteristics,teaching and training,designed to provide theoretical teaching and reference support and training.Methods: The kinematic index of this study uses Sony DSC-RX10 M camera and German SIMIMOTION 3D technology action analysis software for action image acquisition,data synchronization and smoothing processing.The EMG metrics were collected and synchronized and filtered using the US Noraxon Ultium EMG Wireless surface EMG Tester and the Finnish Mega Win surface EMG analysis software.Results:1.In the stage of lifting the center of gravity,high-level athletes are more powerful than secondary athletes,including dorsal broadsi（p=0.005 * *）,biceps（p=0.001 * *）,latissimis（p=0.002 * *）,rectus femur（p=0.001 * *）,and trapezius（p=0.035 *）.High-level athletes do the biggest muscle work is the triceps,biceps,rectus femur muscle.The active muscles of secondary athletes are triceps,rectus and deltotois.Joint angle change trend of high-level athletes is obvious,the human body movement speed is faster.Second-class athletes,the overall joint angle changes are gentle,the human body movement speed rhythm is slow.This shows that the movement stability of the secondary athletes is poor,the movement connection is not obvious,the center of gravity is not fully supported up has begun to enter the next stage.2.The forward long step stage,the muscle group with very significant differences in force are triceps（p=0.000 * *）,latissimus（p=0.003 * *）,and significant differences are rectus ventris（p=0.033 *）,rectus femur（p=0.012 *）.High-level athletes mainly do work muscle group for triceps,rectus abdomen,rectus femur muscle.The main muscles of secondary athletes are biceps,deltriangle muscle,and thoracic muscle.Hip flexion decreased significantly in high-level athletes,the elbow angle increased with the center of gravity,and the center of gravity to the bar distance increased significantly.Secondary athletes to the center of gravity to the bar distance basically no change,the elbow began to bend,hip flexion becomes larger.This shows that the secondary athletes have not fully launched their center of gravity,and have begun to accelerate the action.3.The front loop to the overhang stage,the rectus femur force（p=0.001 * *）,with significant differences between the rectus abdominis（p=0.012 *）and biceps（p=0.044 *）.High-level athletes mainly force muscle is rectus femur,the rest of the muscle group is below 10% of their own MVC value.The muscle group with more obvious strength has biceps muscle,rectus abdominal muscle and latissimus dorsal muscle.High-level athletes have smaller hip flexion than the previous stage,the thigh surface is closer to the trunk,the overall elbow joint remains straight,but there is a significant bar sinking movement near the vertical position.The center of gravity to the bar distance is also further increa significantly changed compared with the previous stage,the hip flexion is also more open,and the arms are bent when they reach the cantilever.The whole process of the secondary athlete acceleration intention is obvious.sed.The distance between the center of gravity and the bar is still not4.The horizontal position to the bar stage back to the loop to the bar,the force state of large thoracic muscles（p=0.001 * *）and delealis（p=0.009 * *）are very different.There were significant differences in biceps（p=0.015 *）,triceps（p=0.026 *）,latissimus（p=0.046 *）,and rectus abdominis（p=0.039 *）in force.The muscle groups of high-level athletes mainly involved in doing work are the deltrangulid,biceps and thoracic macromuscles.The obvious muscle groups of secondary athletes are triceps,dorsal latissimus and rectus abdominis.High level athletes have subtle elbow arms to shorten the torque movement details,second level athletes have no obvious keep up with the movement.5.The horizontal position to the end stage,the triceps（p=0.006 * *）varied significantly.Significant differences were observed in trimuscle（p=0.028 *）and dorsal latissimus（p=0.014 *）.After-bar levels to the end,muscle force in high-level athletes was relatively average,with muscle populations with over 10% MVC values being only 1 – 2.The overall triceps and dorsal muscles of secondary athletes were stronger,with an average of 4-5 muscles exceeding10% of the MVC values.Joint angles for all people showed similar trends at this stage.Compared with high-level athletes,the overall center of gravity speed of secondary athletes drops too fast.conclusion:1.The process of riding the front loop can be divided into five stages: lifting the center of gravity,inverted forward far span,loop to overhang,loop to the back level of the bar,and back level to the end of the bar.2.The change of the joint Angle of the secondary athletes does not conform to the technical principle,the overall speed change is relatively average,and the absence of the center of gravity is the main reason for the small range of movement.Early acceleration in the first half is an important factor causing insufficient speed in the second half.3.In the movement process of the second-class athletes,the overall muscle mobilization is unreasonable,and the failure to master and use the characteristics of the instruments are all the reasons for the poor stability and low quality of the movements.The first stage of less muscle force than athletes and first class athletes are the main reasons for the lack of exercise speed.4.Provide different auxiliary exercises and elastic belt effective intervention for time and space feeling,special muscle strength and correct muscle group feeling and correct joint angle.It is suggested to strengthen movement concept and muscle memory before learning,establish correct understanding and accurate impression,and protection and help,straight arm high position,forward flexion,wrist shoulder turning,and leg braking.5.Protection and help of the front loop According to the teaching purpose and practice level,use the front and back stations,which are mainly to support,support and hold,and conduct the classroom practice of grouping and protection and help when teaching. |
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