The Men's Table Tennis Players Play Backhand Upspin And Backspin Loops Technical Surface Electromyography Of Movement

Research objectives:With the vigorous development of the sport,backhand loop technology is becoming more and more important in the role of the game,this paper attempts to electrical technology and motion capture technology is introduced into the backhand loop technology in the study,the table tennis players pull backhand topspin and backspin loop to hit the ball in the process of upper shoulder,elbow,wrist joint and body main power muscle testing,and combining the multidisciplinary knowledge such as sports anatomy,sports biomechanics analysis,hope to have this complete by combining action to find the changes in the velocity of each joint situation when the muscle power between timing and power law,The difference of muscle activity between upspin and backspin curveball players is compared,which provides some basis for the scientific training of backhand curveball technique in the future.Research methods:in this paper,10 male table tennis players of the first grade were performed with the use of Delsys surface electromyography instrument and SIMI Motion capture system,and the electromyography signals and Motion capture were collected synchronously with the backhand upspin and backspin arc movements.During data collection,the server served topspin and backspin to the backhand position of the subject in the form of multiple balls according to the requirements of the experiment design.During the test,the subject was required to hit the diagonal ball with his maximum strength and keep the movement stable.Five complete moves were collected for each technique.The collected emg signals are processed by filtering,smoothing,rectifying and filtering in the EMGworks Analysis system of the data Analysis system matched with the Delsys emg tester to obtain the timing sequence of each muscle force,integrated emg value and RMS value,etc.The collected motion-capture images obtained in SIMI Motion Motion capture system were automatically captured,manually supplemented,and low-pass filtered to obtain time-velocity data.Excel and SPSS26.0 were used to conduct mathematical statistics and paired sample T test on the obtained data,and then the two technical actions were analyzed.Research results:(1)the upper limb muscles,such as brachioradialis,triceps and deltoid,have a high degree of activation,while the erector spinalis and gastrocnemius start to activate earlier,and the trapezius and deltoid have a longer continuous activation time.(2)the brachioradialis and deltoid muscles were activated to a high degree by backhand pull-down rotation of the globoid,and the medialis femoris,gastrocnemius and deltoid muscles were activated earlier,while the brachioradialis and deltoid muscles were activated for a long time.(3)backhand topspin and backspin looping each muscle in medial gastrocnemius muscle,muscle activation time,the external oblique muscle and shaft sma has very significant difference(P<0.01),in the radial muscle,deltoid,humerus triceps place has significant difference(P<0.05),there was no significant difference in other muscle(P>0.05).(4)the amplitudes of the root mean square of the overhand and underhanded arcs were significantly different in the gastrocnemius and the external oblique(P<0.01),and significantly different in the vastus medialis,erector ridge,brachioradialis and latissimus dorsi(P<0.05),but not in other muscles(P>0.05).(5)the speed at the joint during the swing is shoulder joint<elbow joint<wrist joint<racket.At the beginning of the swing,the maximum speed and the end speed,there were significant differences between the upspin and backspin arcs(P<0.05).There were significant differences between the two techniques in the swing stage(P<0.05).Research conclusions:(1)the brachioradialis,triceps,deltoid and other small muscles are mainly used to pull the backhand loop.The lower limbs and trunk muscles play a coordinating role in the movement.The transfer of power first by the leg muscles,the waist rotation,drive the trunk will be the strength of the savings to the swing arm,finally through the "swing","elbow","wrist" will release the strength.(2)the difference between the two techniques is mainly manifested in the fact that the pull-down spiral ball exerts more power on the muscles of legs and waist and abdomen than the pull-up spiral ball.During the swing,the speed of upswing at shoulder,elbow,wrist and racket is greater than that at downswing,and the power of upswing is more concentrated.(3)hip rotation can improve the quality of backhand upswing shots,and strengthening the wrist swing before hitting can improve the quality of backhand downswing shots.