Kinematic Analysis Of Different Levels Of Table Tennis Athlete's Short Forehand And Backhand Pulling Technique Combination

Purpose:To explore the difference between the main batting effects of each single technique of the national first-level-level and national second-level male table tennis players with short forehands and backhand pull techniques,that is,the speed of table tennis that is mainly related to two of these single techniques,Rotation,and drop points;further from the time characteristics of each phase of the collected movement;kinematic indicators of the right lower limb ankle,knee,and hip joints;data on the change of the body's center of gravity;and right upper limb wrist and elbow joints And shoulder kinematics,combined with table tennis teaching and training experience to analyze the possible factors leading to this difference,and provide some theoretical references for future athletes' training of this combination of techniques.Methods: This paper selects 20 male table tennis players(10 national first-level-level,10 national second-level)male table tennis players from China Table Tennis College of Shanghai University of Sport.The high-speed camera and infrared high-speed motion capture system are used for short-handed forehands and backhands The bit-pulling technique is used to test the kinematic indexes of the related batting effects,the main joints of the upper and lower limbs,and the center of gravity of the body.Excel and SPSS26.0 are used to process the obtained data and independent sample T test.Results:1)Ball hitting effect: the speed of the forehand position in the first-level group is shorter than that of the second-level group(P<0.05);the ball speed is not significantly different(P>0.05).2)Action time: The swing,forehand,and reduction phases of the forehand swing in the first-level group were shorter than those in the second-level group(P<0.05).3)The main joints of the upper limbs: the forehand position is short,the flexion/extension angle of the shoulder and wrist joints at the end of the draw and the welcome phase of the two groups;the adduction/extraction of the shoulder joint at the start of the draw and the draw Significant differences were found in the panning angle and the panning angle and the panning angle at the end of the shoot(P<0.05).Pulling the ball in the backhand position,the changes in the elbow and wrist joint angles of the two groups were the largest during the swing and onset phase;the wrists in the two groups were opposite in the direction of motion on the coronal plane.4)The main joints of the lower limbs: the forehand position is short,and the flexion/extension angle of the hip joint at the end of swing is greater than that of the second-level group(P<0.05).In backhand pull,the flexion/extension angle of the knee joint in the first-level group was larger than that in the second-level group(P<0.05).5)Change of body center of gravity: The difference in height of the center of gravity of the two groups was significant at the end of the swing of the forehandposition and the swing of the backhand ball(P<0.05),and there was no significant difference in the change of the center of gravity height of the two groups(P>0.05),the body weight of the first-level group is lower than that of the second-level group.Conclusions:1)In the combination technology,the rotation speed of the forehand position in the first-level group is shorter than that in the second-level group;the speed and drop point of the backhand pulling ball are also better than those in the second-level group,but there is not much difference between the two groups in terms of hitting speed.The forehand swing of the first-level group is more sufficient than that of the second-level group;the time of swing,follow-up and reduction is shorter,indicating that the athletes of the first-level group have stronger explosive power during the swing and have better brake reduction ability.2)In the short forehand position,the flexion/extension angles of the shoulder and wrist joints of the first-level group at the end of the shoot are significantly different from those of the second-level group.There is also a significant difference between the inside and outside rotation angles at the end of the draw,so there is more room for force;the flexion/extension angles of the shoulder and wrist joints during the swing phase are greater,the angular rate is faster,and they have more explosive power.3)In the backhand pull,the changes in the elbow and wrist joint angles of the two groups were greatest during the swing and onslaught phase;the first-level group's wrist movements were more reasonable and the stored potential energy was greater during the draw phase.4)In the short forehand position,the hip joint of the first-level group has a larger pre-flexion angle than the second-level group at the end of the swing,and has better braking reduction.In the backhand pull,the knee joint of the first-level group flexed more than the second-level group at the end of the draw and swing,with greater elastic potential energy and good braking reduction ability.5)During the whole process,the height of the body center of gravity of the first-level group is slightly lower than that of the second-level group,and there is a significant difference at the end of the swing,and it has a faster moving ability.