Immediate Effect Of Vibration Stimulation On Cross-Education Of Knee Extension Force

Research objective:with the popularity of functional training theory,unilateral strength training has been applied widely in fitness,competitive training and sports rehabilitation.Studies have shown that unilateral strength training can produce a "Cross education effect" due to the neurological adaptation of homologous muscle,which means the strength training of one side can also develop the homologous muscles of another side(untrained side).Vibration training refers to a special training mode in which the body fully or partially contacts the vibrator and receives rhythmic vibration training.Unilateral training has been widely applied in vibration training,but few studies focus on the effect of vibration on the cross education effect of unilateral training,which is not good for the formulation of scientific training plan.The purpose of this study is to investigate the effects of vibration on the cross education effect of low-intensity resistance training,and provide a reference for more scientific development of relevant training programs in the future.Research methods:The subjects were 16 healthy men with squatting strength more than 1.5 times their weight in Peking Sports University School of Education.The test method was: the subjects were tested for different knee extension strength before and after intervention.Interventions were as follows: the knee joint was squatted with one leg at 120 and 90 degrees on the shaking table to measure the strength and surface electromyography of the extensor muscle group,so as to explore the influence on the cross-migration of the other leg.There were two groups(120degrees squatting for 1 minute,90 degrees squatting for 30 seconds,clearance for 2minutes,total 9 minutes),vibration frequency for 30 Hz and amplitude for 4 mm.The statistical method is: paired samples T-test with spss.Research results:The peak moment of knee extension strength of non-dominantleg was significantly increased when vibration stimulation was applied to dominant leg(p=0.015);the time taken to reach the peak moment of knee extension strength did not change significantly;the force generation rate(RFD)of 0-100 ms and100-250 ms did not increase significantly(p>0.05);the root mean square of rectus femoris myoelectrics of non-dominant leg after vibration stimulation was applied to non-dominant leg.(RMS)had significant difference(p=0.001).The RMS of rectus femoris before and after vibration training had significant difference(p=0.042)under the condition of 20% weight knee extension load,and the RMS of rectus femoris before and after vibration training had significant difference(p=0.036)under the condition of maximum knee extension load.Conclusions :(1)Low-intensity vibration stimulation can improve the maximum strength of knee extension and the activation level of rectus femoris muscle of non-dominant leg after squatting training,and enhance the effect of strength cross education.(2)EMG is more sensitive than strength in the test of cross education effect.