Comparative Study And Analysis Of The Effects Of Frog Jump, Squat Jump And Jump Depth Training On Lower Limb Muscle SSC

Frog jump,squat jump and deep jump are common exercises to develop the fast muscle strength of lower limbs.It is of great significance to study the biomechanical characteristics of lower limb muscles of volleyball players,not only in enriching the theoretical system of strength training,but also in meeting the actual needs of strength training.By analyzing and discussing the results of kinematics,dynamics and EMG test of 8 lower limb muscles after 8 weeks' training intervention,the biomechanical characteristic frame structure of lower limb muscles during deep jump is established,in order to provide valuable theoretical reference for sports training practice.The main methods of this study are test method,Experimental method,interview method,logical analysis method,mathematical statistics method,etc.The experimental indicators were determined by questionnaire and interview from experts.Kistler three-dimensional dynamometer and portable wireless telemetry surface electromyography testing system were used for testing.The results : 1.Through the analysis of experimental data,it is concluded that there are differences in time variation of frog jump group,squat jump group and deep jump group in vertical jump.The change of frog jump group before and after training is 0.01 s,squat jump group before and after training is 0.02 s,and the time of landing improvement is the most in deep jump group,with the change of 0.03 s.2.Buffer phase The training buffer time of frog jump group increased by 0.01 s,squat jump group increased by 0.01 s,and the variation of deep jump group increased by 0.02 s before and after training.The deep jump training has a significant effect on the buffer action of athletes' muscles.3.During the pedal-stretch period,the time change of frog jump before and after training is 0,the time of squat jump group increases by 0.01 s,while that of deep jump group decreases by 0.02 s.4.Among the iEMG values of the three groups before and after training,the change of the biceps femoris in frog jump group was the most in the same time.After squat jump training,the medial femoral muscle increased the most.In the deep jump group,the integral EMG of the lateral femoral muscle changed most in the same time.5.RMS values before and after training in the three groups,the medial femoral muscle was the biggest change in frog jump group before and after training,followed by the rectus femoris muscle.The medial femoral muscle and rectus femoris muscle were the most stimulated in squat jump group,and the medial femoral muscle,rectus femoris muscle and lateral femoral muscle were all stimulated in deep jump group.6.In terms of flight time,the growth of frog jump group and push-stretch group is 0.01 s,while that of deep jump group is 0.02s;in terms of take-off speed,the growth of frog jump group is 0.02m/s,squat jump group is 0.01m/s,and that of deep jump group is 0.03m/s.In terms of the instantaneous maximum force of landing,the frog jump group increased 59.83 N,squat jump group increased 63.54 N and deep jump group increased 71.438 N.Research conclusions: 1.In jumping movements,the pedal-extension period of lower limb muscle landing is longer than the buffer period,that is,the time of centrifugal contraction is longer than that of centripetal contraction.2.Comparing the training values of frog jump group,squat jump group and deep jump group,in terms of the reduction of cushioning time and pedaling time of lower limb muscles,the most significant reduction of centrifugal and centripetal contraction time before and after the deep jump group training.3.In the lower limb muscle integral EMG,the growth value of the biceps femoris was the largest in the frog jump group,the growth value of the medial femoral muscle integral EMG was the largest in the squat jump group,and the change of the lateral femoral muscle integral EMG was the largest in the deep jump group.Compared with the three training groups,the integral EMG growth of the same muscle is different in different groups,and most of the muscle growth is the most significant in the deep jump group.4.The RMS values of lower limb muscles in frog jump,squat jump and deep jump groups changed during the buffer period and pedal-extension period.The RMS values of the same muscle during the buffer period were larger than those during pedal-extension period.Most of the RMS values of the same kind of muscle change most in different training methods.5.Before and after training,the order of time increment is deep jump group > squat jump group > frog jump group;the order of speed increment is deep jump group > frog jump group > squat jump group;the order of maximum force increment in landing stage is deep jump group > squat jump group > frog jump group.