不同程度紧身压迫对踏蹬运动中股内侧肌sEMG变化特征的影响

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

目的:利用表面肌电相关指标定量反映不同强度负荷的匀速踏蹬运动至疲劳过程中,不同程度紧身压迫对股内侧肌sEMG变化特征的影响,进而探讨紧身压迫度对肌肉活动的效用及其内在机制。方法:随机抽取未进行过系统踏蹬训练的青年健康男性受试者10名,分别以下肢无紧身压迫、中度紧身压迫、高度紧身压迫状态完成中强度和大强度负荷的匀速踏蹬运动至疲劳测试,对同步采集的股内侧肌iEMG和MF肌电指标数据进行分段和标准化处理,并采用三因素方差分析和事后多重比较检验考察各组实验数据间的差异。结果:1)运动后期,紧身压迫对iEMG及MF变化幅度的总效应均有影响,且在与运动强度发生交互作用时,这种影响效应更为明显。2)与无紧身压迫相比,中度紧身压迫不改变中强度负荷运动中iEMG(%)值的增长和MF(%)值的降低幅度;但却使大强度负荷运动后期iEMG(%)值的增长和MF(%)值的降低幅度均有所下降。3)与无紧身压迫相比,高度紧身压迫使中强度负荷运动后期iEMG(%)值的增长和MF(%)值的降低幅度均有所下降;但却使大强度负荷运动后期iEMG(%)值的增长和MF(%)值的降低幅度均有所上升。结论:外加中度紧身压迫在大强度踏蹬运动后期与外加高度紧身压迫在中等强度踏蹬运动后期对股内侧肌的作用相似,均利于维持局部肌肉收缩的输出功率及外周运动单位动作电位的传导速率,在一定程度上有助于延缓肌疲劳和延长运动时效;相反,外加高度紧身压迫在大强度踏蹬运动后期则会加速肌疲劳的发展进程。

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 Hoe 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 （G） 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 o{ 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.