Comparative Analysis Of Kinematics And Emg Characteristics Of Backhand Volley Technique Of Male Tennis Players Under Different Ball Speed Conditions

Objective:This study mainly tested the backhand volley technique of male tennis players through motion capture system and s EMG acquisition system.The aim is to analyze the kinematics and s EMG characteristics of backhand volley technique in the success and error of athletes with different ball speed conditions,compare the differences,and provide theoretical and practical basis for coaches,athletes and tennis enthusiasts to improve the training of forehand interception technique.Method:1.Subjects: 10 male tennis players.2.Scheme: The subjects station is located at 1.8-2m in the distance of the court serve line.The tennis serve machine is placed in the middle of the bottom line of the opposite half of the subject,and the ball points to the backhand of the subject,and the height through the central net belt is between 0.4m-0.6m.At the beginning of the experiment,the subjects began to backhand volley the ball at the same ball speed issued by the serving machine.The subjects should volley the ball sent by the serve machine to the two areas three times as required,and then pause the experiment and rest for two minutes.Then adjust the ball speed of the serving machine and continue the experiment,requiring a total of three ball speeds(70 km/h,90 km/h,110 km/h).3.Data analysis: The 3D infrared motion capture system and Noraxon3.14 wireless s EMG acquisition and analysis system were used to collect the motion information,and the analysis software of each system and Excel,SPSS and other tools were used for parameter calculation and analysis.Results:1.Under different ball speed conditions,the right shoulder horizontal abduction Angle of the three groups hit the ball is greater than the volley error,and all have significant differences.However,the horizontal abduction angle of the right shoulder joint between the three groups compared the athletes at the time of successful volley did not have a significant difference.2.Under different ball speed conditions,the Angle of the racket surface of the players in the three groups is significantly less than that of the volley error,and all of them have significant differences.However,the comparison of the three groups was not significant.3.Under the conditions of different ball speed,the three groups of knee Angle is less than the volley error,but the body center of gravity forward distance is greater than the volley error,and the ball speed of 70 km/h and 90 km/h,the athletes of the body of the forward distance has significant difference and very significant difference respectively.However,the Angle of the knee joint and the forward distance of the body center of gravity between the three groups.4.At the ball speed of 90 km/h and 110 km/h,the contribution rate of the muscles measured during the strike stage was in the same order,and the biceps brachialis was 70 km/h.When athletes volley mistakes,the contribution rate of the measured muscles is chaotic.Conclusion:1.Under different speed conditions,the player is successful volley moment shoulder level abduction Angle is greater than the volley error,but the body roll Angle is less than the volley error,shows that players use backhand volley speed of the ball,must ensure the shoulder level abduction,put the ball in front,at the same time should avoid excessive body roll and break the balance,cause the volley error.2.Under the condition of different ball speed,the athletes volley successful surface Angle are close to vertical,and are less than the volley Angle,therefore,in the backhand volley stage should pay attention to the control of the Angle,the Angle more close to vertical,can improve the volley quality,and not because of the change of ball speed and change the Angle of the surface.3.Under different ball speed conditions,the right knee Angle is less than the volley error,but the successful volley forward distance of the body is greater than the volley error,therefore,the ball,the ball needs to bend the knee in a reasonable range,effectively use forward with the power of the body to coordinate the arm swing,and improve the stability of the body when volley,improve the quality of the volley.4.Under the condition of different ball speed,the player stroke successful stage of upper limb muscles has consistency,so when the players in the net using backhand volley technology handle different ball speed of the ball,pay attention to keep the consistency of action,not because of the influence of the speed of the ball action,which lead to a series of muscle compensation,affect the main force muscle,affect the quality of the ball.