Surface Electromyographic Features Of Lower Limb Muscle During Different Phase Of Gait Cycle In Young People With Different Physical Activity Levels

Objective:Young people with different levels of physical activity may have differences in lower limb muscle strength due to their specific habits and exercise habits in daily life and learning.Therefore,this study was conducted in young people with different physical activity levels to investigate the effect of physical activity level on the surface EMG and co-activation of lower limb muscles in walking.Methods:Using the International Physical Activity Questionnaire(IPAQ-L-C-usual week)to classify physical activity levels,MP150 as a research tool.To explore the characteristics of lower limb muscle activity in young people with different levels of physical activity during the gait cycle.By analyzing the experiment data,summarizes the surface EMG characteristics of eight lower limb muscles(RF,VM,VL,BF,TA,MG,LG,SO)during the gait cycle.The Coactivation Index(CI)was used to determine the degree of co-activation of lower limb muscles,explores differences in lower limb muscle co-activation in young adults with different levels of physical activity during the gait cycle.Results:(1)There was no significant difference in gait speed and gait cycle time among people with different physical activity levels(P>0.05).(2)(1)During IC,the differences in BE i EMG between medium physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in MG i EMG between high physical activity levels and medium physical activity levels were statistically significant(P<0.05).(2)During LR,the differences in LG i EMG between high physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in LG muscuular contribution between high physical activity levels and low physical activity levels were statistically significant(P<0.05).(3)During MSt,the differences in LG muscuular contribution between high physical activity levels and medium physical activity levels,high physical activity levels and low physical activity levels were statistically significant(P<0.05).(4)During TSt,the differences in LG muscuular contribution between high physical activity levels and medium physical activity levels,high physical activity levels and low physical activity levels were statistically significant(P<0.05).(5)During PSw,the differences in BF i EMG between medium physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in BF muscuular contribution between high physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in BF RMS between medium physical activity levels and low physical activity levels were statistically significant(P<0.05),the difference in TA RMS between high physical activity levels and medium physical activity levels were statistically significant(P<0.05),the difference in LG and MG muscuular contribution between high physical activity levels and medium physical activity levels were statistically significant(P<0.05).(6)During ISw and MSw,there were no significant difference in the surface EMG indexes of the lower limb muscles among people with different physical activity levels(P>0.05).(7)During TSw,the differences in BF i EMG and RMS between medium physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in BF muscuular contribution between high physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in TA RMS between high physical activity levels and medium physical activity levels were statistically significant(P<0.05),the differences in MG muscuular contribution between medium physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in MG RMS between high physical activity levels and medium physical activity levels,high physical activity levels and low physical activity levels were statistically significant(P<0.05),the differences in LG muscuular contribution between high physical activity levels and medium physical activity levels were statistically significant(P<0.05).(3)The difference in CITH between the three groups was statistically significant(P<0.05),the medium physical activity levels' CITH was higher than others.The difference in CISH between the three groups was statistically significant(P<0.05),the high physical activity levels' CISH was higher than others.The difference in CITOT between the three groups was statistically significant(P<0.05),the medium physical activity levels' CITOT was higher than others.Conclusion:(1)There was no significant effect of physical activity level on gait speed and gait cycle time in young people walking at natural gait speed.(2)The physical activity level of young people had a significant effect on the surface EMG indices of the lower limb muscles in all phases of the gait cycle.Different muscles in IC,LR,MSt,TSt,PSw and TSw showed difference between groups with different physical activity levels.(3)High physical activity levels are better able to use the lower limb muscles to maintain body stability during all phases of the gait cycle,and the surface EMG indices of the BF,TA,MG and LG can better reflect the effect of physical activity levels on the surface EMG of the lower limb muscles during the gait cycle.(4)During natural speed walking,the physical activity level had an effect on the coordination of young people.The medium physical activity levels' CITH was higher than others,indicating a higher requirement for knee joint stability when walking;the high physical activity levels' CISH was higher than others,indicating a higher requirement for ankle joint stability when walking.