Study On The Effect Of Sole Thickness On EMG Signal Of The Lower Limbs' Muscles During The Jump

Purposes:By the test of the subjects who wearing different sole thickness sports shoes,with the help of the s EMG signal analysis method,the present research explored the impact of changing sole thickness on lower extremity muscle's activity characteristics during the jumping movement.Methods:Eight university students who were in good health and had no history of leg injury or surgery participated in the test.A 16-channel wireless s EMG test system(Noraxon,USA)with a sampling frequency of 1500 Hz was used to get the original EMG data.A built-in camera was used to capture the subject's motion video synchronously.Myo Research XP Master Edition analysis software(Noraxon,Inc.,USA)was used to preprocess the raw electromyographic signal parameters.The pre-processed signals were analyzed and calculated using MATLAB software.Results:In take off stage of counter movement jump(CMJ),the gastrocnemius integrated EMG(69.7±11.6?Vs,71.3±15.6?Vs,75.6±19.3?Vs and 76.5±11.9?Vs)were higher than those of other test muscles when wearing different thicknesses shoes.In the stage of landing,the integrated EMG of tibialis anteriorthe(61.8±13.6?Vs,63.2±16.7?Vs,67.7±19.3?Vs and 68.8±13.2?V)were higher than those of other test muscles,respectively.The same muscle force characteristics are exhibited in Squat Jump(SJ)and standing long jump.One-way ANOVA analysis showed that during the CMJ extension phase,the change in sole thickness had a significant effect on the integrated EMG ??of tibialis anterior(F=0.230,P<0.05)and also on gastrocnemius(F=0.487,P<0.05).In CMJ landing stage,changes in sole thickness had a significant effect on the integrated EMG ??of tibialis anterior(F=0.093,P<0.05)and also on gastrocnemius(F=0.087,P<0.05).The same results were obtained during the extension and landing stages of SJ and standing long jump.Conclusion:1.The activation of gastrocnemius was the highest in the extension stages of CMJ,SJ and standing jump,and in landing stage,the tibialis anterior was thehighest.2.All the EMG data increased accompanied with the increasing of sole thickness which indicated that the degree of muscle activation in human lower extremity will increase when sole thickness changed.3.When jumping,sole thickness should be more effective on tibialis and gastrocnemius activation.The muscle activation increase rate of the shank muscle group is greater than the thigh.