Bohannon R W, Reed M L, Gajdosik R L
School of Allied Health, University of Connecticut, USA.
Clin Biomech (Bristol). 1990 Feb;5(1):17-22. doi: 10.1016/0268-0033(90)90027-4.
This study was designed to determine the extent to which knee flexion torques would differ when submaximal hamstring muscle contractions were evoked by constant levels of electrical stimulation and when the pelvifemoral angle was increased. Nineteen healthy subjects (ten women and nine men) underwent electrical stimulation of the hamstring muscles while randomly positioned either supine, sitting upright, or sitting leaning forward. The pelvifemoral angle for each position was measured from lateral photographs: the knee flexion torque was calculated from the knee flexion force, and lever arms measured directly at a constant knee angle. A repeated measures ANOVA demonstrated significant differences for pelvifemoral angles (F = 485·00, P < 0·001) and knee flexion torques (F = 21·97, P < 0·001) among the positions. The mean torques in the upright and leaning forward positions were 2·2 and 3·7 times greater, respectively, than mean torques in the supine position. The increase between the supine and leaning forward positions exceeded the increase previously reported in the literature for subjects performing maximal voluntary knee flexion efforts.
本研究旨在确定在通过恒定水平的电刺激诱发次最大程度的绳肌收缩以及增加骨盆股骨角度时，膝关节屈曲扭矩会在多大程度上有所不同。19名健康受试者（10名女性和9名男性）在仰卧、坐直或前倾坐姿的随机体位下接受绳肌的电刺激。每个体位的骨盆股骨角度通过侧位照片测量：膝关节屈曲扭矩由膝关节屈曲力计算得出，杠杆臂在恒定膝关节角度下直接测量。重复测量方差分析显示，各体位之间骨盆股骨角度（F = 485.00，P < 0.001）和膝关节屈曲扭矩（F = 21.97，P < 0.001）存在显著差异。坐直位和前倾位的平均扭矩分别比仰卧位的平均扭矩大2.2倍和3.7倍。仰卧位和前倾位之间的增加幅度超过了先前文献中报道的进行最大自主膝关节屈曲努力的受试者的增加幅度。
