Effect of Tight-fitting Sportswear of Different Compression Degrees on Variation Characteristics of sEMG on Vastus Medialis during Cycling Motion

Objective:Index data from sEMG were used to reflect the influence of different tight compression degrees on variation characteristics of sEMG on Vastus Medialis in different intensity load during cycling motion to fatigue,and then further explored its utilities and internal mechanism on muscle activity.Methods:Selected 10 young healthy male volunteers without cycling training experience randomly as subjects to complete uniform cycling motion to fatigue in moderate and high intensity load on bicycle ergometer with no compression,medium compression and high compression at lower limb respectively.Recorded The original signals of sEMG on Vastus Medialis through the motion process which was divided into 10 segments.After standardized processing of the data from iEMG and MF,compared and analyzed the differences between each set of data by three-factor variance analysis and Post Hoc Multiple Comparisons Test.Results:1) During the later stage of cycling motion,tight compression had influence on the change range of iEMG and MF,which was more obvious when it interacted with exercise intensity.2) Compared with no tight compression,medium tight compression could not change general increasing range of iEMG(%) and reducing range of MF(%) during this cycling movement in moderate-intensity load,which made both of them,however,declined during the later stage of cycling motion in high-intensity load.3) Compared with no tight compression,high tight compression made general increasing range of iEMG(%) and reducing range of MF(%) declined during the later stage of cycling motion in moderate-intensity load,which made both of them,however,increased during the later stage of cycling motion in high-intensity load.Conclusions:During the later stage of cycling motion,plus medium tight compression in high-intensity load and plus high tight compression in moderate intensity load showed similar effects on Vastus Medialis to maintain output power of muscle contraction and transmission rate of action potential,which may be helpful to delay the muscle fatigue and improve the sport performance to some extent.On the contrary,plus high tight compression accelerated muscle fatigue during the later stage of cycling motion in high-intensity load.