Brask B, Lueke R H, Soderberg G L
Phys Ther. 1984 Mar;64(3):324-9. doi: 10.1093/ptj/64.3.324.
The purpose of this study was to determine electromyographically if significant differences in level of electrical activity in the vastus medialis, rectus femoris, biceps femoris, and semimembranosus/semitendinosus muscles occurred during the concentric and eccentric phases of a 4- and 8-in lateral step-up exercise. Twenty-nine subjects with no pathological condition of the knees participated in the study. The surface electromyograms obtained were processed by linear envelope detectors and normalized, in percentage, to a maximum voluntary contraction of each subject. Within-muscle differences, step height, and contraction type were tested with a two-way analysis of variance. Results revealed that the average values for muscular activity, depending on the height and direction, ranged from 24 percent to 60 percent for vastus medialis, 8 percent to 23 percent for rectus femoris, 3 percent to 9 percent for biceps femoris, and 4 percent to 9 percent for semimembranosus/semitendinosus muscles. All muscles were significantly more active at the 8-in height than at the 4-in height. The concentric phase produced significantly greater activity (p less than .001) than the eccentric phase at each height except for semimembranosus/semitendinosus muscles, where no significant difference existed. The results of this study are discussed with respect to the limited role that the tested hamstrings and quadriceps femoris muscles play in preventing anterior shear of the tibia during the lateral step-up exercise.
本研究的目的是通过肌电图测定，在4英寸和8英寸的侧向登台阶运动的向心和离心阶段，股内侧肌、股直肌、股二头肌以及半膜肌/半腱肌的电活动水平是否存在显著差异。29名无膝关节病理状况的受试者参与了本研究。所获得的表面肌电图由线性包络检波器进行处理，并以百分比形式标准化为每个受试者的最大自主收缩。肌肉内部差异、台阶高度和收缩类型采用双向方差分析进行测试。结果显示，根据高度和方向不同，股内侧肌的肌肉活动平均值范围为24%至60%，股直肌为8%至23%，股二头肌为3%至9%，半膜肌/半腱肌为4%至9%。所有肌肉在8英寸高度时的活动明显高于4英寸高度时。除了半膜肌/半腱肌不存在显著差异外，在每个高度上，向心阶段产生的活动均显著大于离心阶段（p小于0.001）。本研究结果围绕所测试的腘绳肌和股四头肌在侧向登台阶运动中防止胫骨前向剪切方面所起的有限作用展开讨论。
