Study On The Effect Of Squatting With Different Standing Posture′s Width On Quadriceps Surface Muscles Training

Purpose:This study combines the characteristics of bodybuilding,using biomechanics and medical imaging research methods and measurement methods,Analyze changes in indicators such as surface electromyography(s EMG),1repetition maximum(1RM)test on the squat,thigh circumference and superficial layer of the quadriceps muscle thickness(MT)before and after the intervention.This study aimed to find the best stance width for training different muscles on the surface of the quadriceps(rectus femoris,vastus medialis and vastus lateralis muscles)for barbell back squat.Explore the activation of different superficial layer of the quadriceps by barbell back squats in different stance widths.Try to solve the problem of the choice and arrangement of target muscle training movement in actual bodybuilding.It provides a theoretical reference for choosing the squat stance width in different superficial layer of quadriceps training in bodybuilding.Methods:This research mainly uses experimental research,30 men from Xi’an Physical Education University majoring in fitness were randomly divided into three groups:a narrow stance squat group(20.90 ± 0.74 years),a shoulder stance squat group(21.00 ± 0.67 years),and a wide stance squat group(20.90 ± 0.57 years).Squat training was performed for 10 weeks(2 times a week,45min-60 min each time).They were instructed to maintain their usual diets and living habit.The narrow squat group uses feet together for barbell back squat,the shoulder stance squat group uses shoulder width barbell back squat,the wide squat group uses 140% shoulder width for barbell back squat.According to the physiological and anatomical characteristics,functions and related training theories of the quadriceps.Before and after the training period,participants were assessed for 1 repetition maximum(1RM)test on the barbell back squat 、 use Color Doppler Imaging for muscle thickness measurement(MT)and measure thigh circumference.Result:(1)After 10 weeks of experimental training,the RMS of the rectus femoris and vastus medialis muscles in the shoulder stance squat group presented statistically significant gains.(P<0.05);The RMS of the vastus medialis muscle in the shoulder stance squat group was significantly higher than that of the narrow stance squat group(P<0.05);The integrated electromyography(IEMG)of the rectus femoris,vastus medialis and vastus lateralis muscles in the shoulder stance squat group after the experiment was significantly higher than that before the experiment(P<0.05);After the experiment,the rectus femoris,vastus medialis muscles integrated electromyography(IEMG)in the shoulder stance squat group were significantly higher than those in the wide squat group(P<0.05).(2)After 10 weeks of experimental training,the maximum strength of the narrow stance squat group,shoulder stance squat group,and wide distance squat group was significantly improved compared to before training(P<0.001).(3)After 10 weeks of experimental training,the thigh circumference of the three groups of participants increased significantly(P<0.01).(4)After 10 weeks of experimental training,all groups presented statistically significant gains in the muscle thickness assessment.Conclusion:(1)After ten weeks of training,three different wides squats have significant activity of the superficial quadriceps muscles.(2)In ten weeks of intervention training,three types of squats can effectively increase 1RM of squats.From the perspective of growth rate,the shoulder stance squat is more effective in improving the 1RM of the squat than the other two.(3)In ten weeks of intervention training,The thickness of the vastus lateralis muscle in the narrow squat group increased the most than the other two groups.The thickness of the rectus femoris muscle in the shoulder distance squat group increased the most.The thickness of the vastus medialis muscle increased the most in the wide stance squat group.(4)The three types of squats activate the medial femoris muscle higher than the rectus femoris muscle and the muscle thickness of the vastus medialis muscle is greater than that of the rectus femoris muscle.