Analysis Of Quadriceps SEMG Of Padding Heel Static Squat Under Different Angles

Introduction:Throughing this study,subjects were in progress of two groups(normal static squat and padding heel squat)under different knee angles,research the sEMG character of left and right quadriceps,and analyse data to compare advantages and disadvantages in two ways,and mainly aims to find out the scientific practice point of padding heel squat.To provide a reasonable scientific basis of padding heel squat.Methods:The subjects are 30 male students in capital university of physical education and sports who major non-sports training and physical and mental condition is good.And they all volunteered for the experiment,their quadriceps and knee haven't happened serious invaliding.Without tired muscle before testing 24 hours.Subjects practice respectively normal static squat and padding heel squat under knee angle of 45 °,60 ° and 75 °.Every angle interval is a week.In the progress of experiment,recording the sEMG signals in the vastus lateralis,vastus medialis and rectus femoris.Experiment data is divided three classes:iEMG,MPF,MF.Using SPSS22.0to analyse the data,using the paired t-test between two groups,using the factor analysis of variance between three angles and five stages.Results:1.The maximum of iEMG in normal static squat and padding heel squat between two legs under three angles are appeared on the knee angle 45 ° of the vastus lateralis,the iEMG of three muscles under the three angles are present the vastus lateralis > vastus medialis > rectus femoris,and padding heel squat group > normal static squat.Three muscles in addition to the right leg rectus femoris,there were no significant difference in 60 °,three angles have significant difference(P ? 0.05,or P ? 0.01).2.The maximum of MPF in normal static squat and padding heel squat between two legs under three angles are appeared on the knee angle 45 °;under three angles,the two groups of MPF are present a strands of vastus medialis > rectus femoris > vastus lateralis.3.The maximum of MF in two groups between two legs under three anglesare appeared on the knee angle 45 °of left vastus lateralis and rectus femoris and right three muscles,and the knee angle of 60 °of left vastus medialis.Three left muscles under three angles,the two groups of MF are present a strands of vastus medialis > rectus femoris > vastus lateralis.Right leg under 45 ° are present a strands of rectus femoris > vastus lateralis >vastus medialis;60 °,padding heel group is rectus femoris > vastus medialis > vastus lateralis,normal static squat group is rectus femoris >vastus lateralis > vastus medialis;two groups under 75 ° is rectus femoris >vastus medialis > vastus lateralis.4.The MPF slope of left and right leg muscles under three angles of padding heel squat all showed a trend of decrease.Vastus lateralis,the rectus femoris of left and right leg MPF slope absolute value is 75 ° > 60 ° > 45 °,vastus medialis is 75 ° > 45°> 60 °.When compared with 45 °,left vastus lateralis under 75 ° show significant difference(P ? 0.05),and60 °haven't.Rectus femoris under 60 ° and 75 ° all show significant difference(P ? 0.05).Vastus medialis under 75 ° show significant difference(P ? 0.05),and 60 ° haven't.5.The MF of left and right leg muscles under three angles of padding heel squat all showed a trend of decrease.The MF slope absolute value of two legs vastus lateralis are 75°> 60 ° > 45 °,rectus femoris,vastus medialis are75 °> 45 ° > 60 °.When compared with 45 °,three muscles of two legs under75 ° show significant differences(P ? 0.05),and 60 ° haven't.Conclusion:1.Padding heel squat is better than quiet squat in the effect of exercising quadriceps.2.Choosing padding heel squat to practice quadriceps and improve muscle strength,in turn,prevent and treat patellar strain,reduce the risk of knee injuries,selecting 45 °is better.And patellofemoral joint pressure is moderate,minimize the risk of secondary damage,so the 45 ° is the more scientific and reasonable practice angle of padding heel squat.