| Objective: To explore the characteristics of body joint angle,angular velocity,muscle activation time,integral EMG value and root mean square amplitude of high-level male volleyball players in Colleges and universities.Methods: 12 high-level male volleyball players from Yanshan University were selected as the experimental objects.Through Qualisys three-dimensional motion capture system and Delsys wireless portable surface electromyography instrument,the technical movement of jumping and floating ball is measured and analyzed,and the body joint angle,angular velocity,muscle force sequence,integral electromyography value and root mean square amplitude value in the air hitting stage are studied.Collect the motion data information and divide the stages according to the judgment criteria of the action stage.Mathematical statistics: using spss23.0 conduct paired sample t-test on the data,use the mean ± standard deviation(M ± SD),sort out and summarize the final data with Excel and Origin software,and compare the data differences between the first and fifth positions of athletes.P>0.05 indicates that there is no significant difference in the results.p<0.05 indicates that there is a significant difference in the results,and p<0.01 indicates that there is a very significant difference in the results.Result:(1)At the beginning of the air stroke,the difference of the left elbow joint angle between the first position and the fifth position was 147.37 ± 12.17 °,135.17 ± 14.79 °,p<0.05.Right knee joint: 160.44 ± 8.21 °,156.27 ± 12.48 °,p<0.01.Left ankle joint:117.83 ± 5.89 °,121.85 ± 8.16 °,p<0.05.Right ankle joint: 114.35 ± 7.89 °,112.01 ±6.68 °,p<0.05.At the end of the air stroke,the difference analysis of the joint angle of the jumping and floating ball technique at position 1 compared with position 5 showed that the right shoulder joint was 144.50 ± 19.15 °,139.13 ± 19.22 °,p<0.05.Right elbow joint:133.32 ± 12.54 °,137.30 ± 14.69 °,p<0.05.Right knee joint: 164.65 ± 12.70 °,155.44 ±18.97 °,p<0.01.There was no significant difference in other joint angles(p>0.05).(2)The difference of the peak value of joint angular velocity between the first position and the fifth position of the left wrist was 213.35 ± 136.08 ° /s,324.61 ± 248.78 °/s,p<0.05.Right hip joint:-405.92 ± 82.98 ° /s,-350.43 ± 115.58 ° /s,p<0.05.Right ankle joint:-525.58 ± 146.66 ° /s,-453.44 ± 149.67 ° /s,p<0.01.The peak angular velocity of other joints had no significant difference(p>0.05).(3)The activation time of the erector spinalis muscle of the jumping and floating ball technique in position 1 was 0.393 ± 0.214 s,0.274 ± 0.234 s,p<0.05.Pectoralis major:0.729 ± 0.436 s,0.509 ± 0.385 s,p<0.05.Right gastrocnemius muscle: 0.277 ± 0.207 s,0.105 ± 0.147 s,p<0.05.The activation time of other muscles had no significant difference(p>0.05).(4)The difference of the left rectus femoris integral EMG value between the No.1position and the No.5 position is 11.66 ± 6.28μV*s、16.14±7.52μV*s,p<0.05.Erector spinalis muscle: 17.92 ± 22.53μV*s,38.82±38.26μV*s,p<0.05。 Right rectus abdominis: 19.98 ± 24.30μV*s、30.69±30.90μV*s,p<0.05.There was no significant difference in other muscle integral EMG values(p>0.05).(5)The difference of the mean square root vibration amplitude of the erector spinalis muscle between the No.1 position and the No.5 position is 61.00 ± 36.23μV、91.76±47.98μV,p<0.05.Brachioradialis muscle: 492.60 ± 453.05μV、763.96±534.89μV,p<0.05.There was no significant difference in other muscle root mean square amplitudes(p>0.05).Conclusion:(1)The shoulder joint angle of the No.1 position is larger than that of the No.5position,and the extension range of the shoulder joint is more.The angle of the hip joint is basically the same,and the athlete’s upper body is more extended when serving the ball in the No.1 position.(2)The fifth position of the peak angular velocity of the upper limb joint on the right side of the body is greater than the first position,and the fifth position of the peak angular velocity of the lower limb joint on the right side of the body is less than the first position.The peak angular velocity of the six joints of the left upper and lower limbs at position 5 is greater than that at position 1,among which the peak angular velocity of the left wrist,the right hip and the right ankle are the most different.(3)In the air hitting stage,the right gastrocnemius muscle is activated preferentially,and finally the triceps brachii force the ball.At this stage,the muscle force shows a similar law.In the air hitting stage,the upper limb muscle tissue plays a major role in the force of the air hitting stage.The role of trunk muscles,rectus abdominis and erector spinalis is more obvious,and the lower limb muscles mainly play a coordinating role in the technical action of the air hitting stage. |
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