【摘要】 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。更多还原

【Abstract】 Objective: The purpose of this study was to analyze the muscle activation levels and co-contraction ratios of vastus medium( VM) and biceps femoris( BF) at different knee angles and g values under whole body vibration( WBV) stimulations. Methods: Forty-six healthy male college students were recruited in this study. They were asked to take Non-Vibration( NV) and WBV at different levels( 0. 98 g,2. 52 g,3. 72 g,5. 61g) with knee flexed at 45,60,90 degrees. EMG signals were recorded simultaneously during NV and WBV and analyzed by paired samples T test,significant level was P < 0. 05. Two-way ANOVA with repeated measures was used to compare EMG levels and co-contraction ratios at different knee angles and different g values,when EMG signals ratio of NV and WBV were dependent variables,g value and knee flexion angle were independent variables. Results:WBV EMG activation level of BF was significantly higher than that of NV when knee flexed at 60 degrees( 0. 98 ~3. 72g) and 45 degrees( 0. 98 ~ 5. 61g). WBV EMG activation level of VM was significantly higher than that of NV at 0. 98 g and 2. 5g when knee flexed 45 degrees. Conclusions: VM and BF muscles activation levels were mainly affected by knee flexion angles,and combination of squat position at knee flexion 45 degrees with 0. 98 /2.52 g WBV stimulations could have better effects on enhancing lower extremity muscle activations.更多还原