Kinematic Analysis Of Backhand Inner Twist And Pull Technique Of Men’s Table Tennis Players Of Different Levels

Research purposes:The backhand twisting and pulling technique in the table tennis table is an advanced service receiving technique that conforms to the current table tennis technical concept.This paper aims to use the kinematics analysis method to collect and analyze the data of the backhand twisting and pulling technique of national first-class and second-class athletes who can skillfully apply this technique,and then compare and analyze the kinematics parameters such as racket speed,trajectory,changes of main joint angles of upper and lower limbs and body center of gravity in each action stage.This paper scientifically discusses the kinematic characteristics of backhand table twisting and pulling technique,provides reference for athletes and table tennis lovers to master backhand table twisting and pulling technique,and is committed to perfecting the gaps and deficiencies in the theoretical system of table tennis technology.Research methods:In this study,two groups of experimental subjects were selected,eight first-class table tennis players in Shaanxi Province and eight second-class athletes majoring in sports training in Xi ’an Institute of Physical Education.All the athletes who participated in the test used the backhand twisting and pulling technique as their main service receiving technique,all of them used the right-hand two-sided reverse glue horizontal racket grip,and had no sports injury history in recent two months.Four high-speed cameras were used to record the technical action of twisting and pulling in the backhand table,and the kinematics parameters such as racket,joint angle,speed and center of gravity were analyzed by SIMI motion,and the data were sorted and statistically analyzed by Excel,Origin2019 b,SPSS.19 and Matlab.Research results:(1)In the racquet stage,the increase of shoulder joint angle of the first-class athletes is greater than that of the second-class athletes,and the increase of elbow and wrist joint angle is less than that of the second-class athletes;The distance of the first-class athlete’s step is greater than that of the second-class athlete’s,the moving distance of the first-class racket is greater than that of the second-class athlete’s,and the time spent in the leading stage is significantly less than that of the second-class athlete’s.(2)In the batting stage,the reduction of shoulder joint angle of the first-class athletes is smaller than that of the second-class athletes,and the increase of elbow and wrist joints is larger than that of the second-class athletes.The first-class athletes play a better role in pushing and stretching lower limbs than the second-class athletes,and the first-class athletes spend significantly less time in batting stage than the second-class athletes.(3)The order of the first-class athletes’ maximum lower limb movement speed is foot,ankle joint,knee joint and hip joint,while the second-class athletes are foot,ankle joint,hip joint and knee joint.(4)In the leading stage of the twisting and pulling technique in the backhand table,the movement track of the racket is to move to the left front and then to the right back and down,to move to the left front and up for a certain distance in the batting stage and then to the right front and up quickly,to continue to move to the right front and up in the swing stage,and to move to the left back and down in the final restoration stage.Research conclusions:(1)The time spent by the second-class athletes is longer than that spent by the first-class athletes in the batting stage,and the racket speed of the two groups of athletes reaches the maximum at the time of touching the ball,and the racket acceleration of the first-class athletes is faster in the batting stage.(2)The angle of the left ankle joint of the first-class athletes is greater than that of the second-class athletes from the end of the racquet to the end of the swing.The angle increase of the first-class athletes’ right knee joint is greater than that of the left knee joint in the batting stage,while the second-class athletes’ knee joint has less kicking and stretching effect.The second-class athletes finished the last step a little later than the first-class athletes,and the change trend of lower limbs in the two groups was roughly the same.(3)In the batting stage,the angle increase of the left and right hip joints and the body torsion of the first-class athletes are greater than those of the second-class athletes,and the first-class athletes exert more force on the hip joints during batting.(4)The elbow movement of the first-class athletes is more stable.At the moment of hitting the ball,the wrist angle of the first-class athletes increases relatively more and the force is more concentrated.(5)The movement speed of each link of the upper limbs of the two groups basically reached the maximum at the time of hitting the ball,and the movement speed from small to large was right shoulder-right elbow-right wrist-right hand,and the hitting action conformed to the principle of "whipping".