The Impact Of Different Zhan Zhuang Postures For Beginners Of Nei Jin Yi Zhi Chan On The Activity Of Lower-limb Muscles

Purpose: This thesis aims to study different stake standing postures for beginners of Nei Jin Yi Zhi Chan,testing the surface electromyography of lower-limbs muscles of different stake standing postures with wireless surface electromyography and exploring the impact of different postures on main lower-limbs muscles during stake standing to provide a scientific basis for the teaching of physical education.Methods: In this study,15 students of sports major with no experience of stake standing training were selected as subjects,and the tester developed by Cometa Company in Italy was used to collect SEMGs of vastus medialis,rectus femoris,vastus lateralis,bicepts femoris,tibialis anterior,gastrocnemius medial,and Gastrocnemius lateral under different postures,including two vertical positions and six different postures.The,the original EMG value was calculated by analyzing software EmgEasyReport Electric value.Microsoft excel 2013 and spss18.0 statistical software are used for the processing and analyzing all original datum.Eight postures: 1.Stand upright with parallel feet at shoulder width.2.Bend knees and squat about 120 degrees with parallel feet at shoulder width3.Bend knees and squat about 120 degrees with both feet spining inward 10 degrees and at shoulder width.4.Bend knees and squat about120 degrees with both feet spining outward 30 degrees and at shoulder width.5.Stand upright with parallel feet 10 cm wider than shoulder.6.Bend knees and squat about 120 degrees with parallel feet 10 cm wider than shoulder.7.Bend knees and squat about 120 degrees with both feet spining inward 10 degrees and 10 cm wider than shoulder.8.Bend knees and squat about 120 degrees with both feet spining outward 30 degrees and10 cm wider than shoulder.During experiment,in addition to the above changes in position,the other parts of body are asked to keep postures of stake standing in Nei JinYi Zhi Chan.That is to hang both arms before chest naturally with forearms parallel with the ground,erect back and head,lookforward,breathe naturally and relax the whole body.Compare the volume of EMG under different positions.Test the paired sample t and analyze with two-factor variance.Results :(1)Under the state of standing upright with parallel feet at shoulder width or standing upright with parallel feet 10 cm wider than shoulder,the medial integral muscle volume of the left gastrocnemius medial muscle was significantly larger than that of the right gastrocnemius medial(P <0.05).(2)Under the state of both feet at shoulder width the medial vastus medialis,rectus femoris,vastus lateralis integral of left side during stake standing was significantly higher than the upright state(P <0.05);the integral of left side of gastrocnemius lateral was significantly lower than the upright state(P <0.05);the integral vastus medialis,rectus femoris,vastus lateralis of right side during stake standing was significantly higher than upright state.(3)Under the state of feet 10 cm wider than shoulder,the integral of the medial vastus medialis,rectus femoris,vastus lateralis of the left side was significantly higher than upright state(P<0.05);the mediastinal myoelectricity of the left gastrocnemius medial muscle was significantly lower than the upright state(P <0.05);the interal of vastus medialis,rectus femoris,vastus lateralis muscle of the right side was significantly higher than the upright position(P <0.05);the mediastinal myoelectricity of the right gastrocnemius medial,muscle was significantly lower than the upright state(P <0.05).(4)The contribution rate of muscle involvement on the lateral side of the left leg gastrocnemius lateral muscle and the lateral leg of the right leg bicepts femoris was significantly higher under the state of feet at shoulder width than under the state of feet 10 cm wider than shoulder(P <0.05).While the contribution rate of the muscle involved in the vastus lateralis was significantly lower under the state of feet at shoulder width than under the state of feet 10 cm wider than shoulder(P <0.05).The contribution of muscle involvement in the medial direction of the left leg gastrocnemius medial under the stete of parallel feet was significantly higher than under the state of feet spining inward about10 degrees.(P <0.05).(5)With parallel feet,the contribution rate of the left rectus femoris muscle under the state of feet 10 cm wider than shoulder was significantlyhigher than under the state of feet at shoulder width.(P <0.05)With parallel feet,the contribution rate of the right gastrocnemius lateral muscle under the state of feet 10 cm wider than shoulder was significantly lower than under the state of feet at shoulder width(P <0.05).Conclusion: 1.Compared to the upright state,squat position,the bilateral lower limb force is more uniform 2.The synergistic mechanism of lower-limb muscles is different under different postures;therefore,It is suggested that beginners adopt the correct posture.3.For untrained practitioners,the muscle control symmetry of both sides is poor;therefore,it is recommended that the leg strength and neuromuscular control symmetry can be trained through prolonged stake standing.