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目的:探讨在不同半蹲屈膝角度情况下接受不同重力加速度(g)的全身振动训练(Whole-body vibration,WBV),下肢股内侧肌(Vastus medium,VM)与股二头肌(Bicepes femoris,BF)激活表现以及两者共同收缩变化。方法:46名健康男性大学生,以表面肌电仪监测惯用腿VM与BF肌电反应。先以3种角度(90、60、45°)半蹲姿势进行无振动刺激(Non-Vibration,NV)测试,再以相同3种屈膝角度接受WBV,振动刺激为随机采用0.98、2.52、3.72、5.61等4种g值。统计学显著性水平为p<0.05,以配对样本T检验比较NV与WBV的肌电信号。因变量为NV与WBV的标准化肌电比例(%MVC),自变量为g值与屈膝角度。以双因素方差分析比较不同g值、角度的肌电反应差异以及共同收缩比例,主效应检验g值与屈膝角度对肌电信号的影响,交互作用检验不同g值振动刺激下屈膝角度差异对肌电信号的影响。结果:BF%MVC在屈膝60°搭配(0.98~3.72)g与45°搭配(0.98~5.61)g的振动刺激情况下,显著高于NV,而VM在屈膝45°搭配0.98和2.52 g时有显著提升肌肉激活的效果。结论:BF与VM的激活程度受半蹲屈膝角度影响较大,而屈膝45°搭配0.98、2.52等2种g值对于BF与VM有较佳激活效果。
Objective: To investigate the effects of whole-body vibration (WBV), Vastus medium (VM) and biceps femoris (Biceps femoris) under different gravitational acceleration (g) BF) activation performance and contraction of the two together. Methods: Forty - six healthy male undergraduates were tested for myoelectrical response (VM) to the legs by the surface electromyography. Non-Vibration (NV) test was performed at three angles (90,60,45 °) in squatting position and WBV at the same three kinds of flexion angles. The vibrational stimuli were randomized to 0.98, 2.52, 3.72, 5.61 and other 4 kinds of g value. The statistical significance level was p <0.05, with paired sample T-test to compare myoelectric signals of NV and WBV. The dependent variable is the normalized myoelectricity ratio (% MVC) for NV and WBV, and the independent variable is the g value and flexion angle. Two-factor analysis of variance was used to compare the differences of myoelectricity and systolic ratio between different g values and angles. The main effect test was used to test the effect of g value and flexion angle on EMG. The interaction between different knee flexion angles and g- The impact of electrical signals. Results: BF% MVC was significantly higher than that of NV in the cases of knee flexion 60 ° collocation (0.98 ~ 3.72) g and 45 ° collocation (0.98 ~ 5.61) g, while VM at flexion 45 ° collocation 0.98 and 2.52 g Significantly enhance the effect of muscle activation. CONCLUSION: The activation of BF and VM is greatly affected by the squat flexion angle. However, 45 ° knees with 0.98 and 2.52 g values have better activation effects on BF and VM.