Ives J C, Kroll W P, Bultman L L
Department of Exercise Science, University of Massachusetts at Amherst.
Res Q Exerc Sport. 1993 Sep;64(3):274-83. doi: 10.1080/02701367.1993.10608811.
Maximally fast, self-terminated elbow flexion movements were performed by 10 male and 10 female college-aged subjects to assess potential gender-related differences in kinematics and the triphasic electromyographic (EMG) pattern. The subjects were instructed to move their forearms as fast as possible through 90 degrees of elbow flexion range of motion and stop as sharply as possible at the terminal point. An electromagnet, set to 0, 40, and 70% of each subject's maximal isometric torque, provided resistance to movement initiation and resulted in quick release movements. Surface EMG was collected from the biceps b. and triceps b. muscles. Results indicated that the males had faster movements and accelerations under all conditions. EMG records indicated that the males had faster rates of EMG rise, particularly in the triceps b., and more tightly coupled reciprocal activation. The quick release afforded faster accelerations for both groups, yet only the males moved faster throughout the full range of motion. Following the quick release, the males differed from the females by increasing the triceps b. EMG amplitude. Hence, the males were able to shorten movement time in quick release movements by increasing triceps b. activation and, thus, braking ability. These results suggest that the females were more neurally constrained than the males with respect to rapid EMG activation of the triceps b., resulting in limits in the braking process.
10名男性和10名女性大学生完成了尽可能快速的、自我终止的肘部屈曲动作，以评估运动学和三相肌电图（EMG）模式中潜在的性别差异。受试者被要求尽可能快地将前臂在90度的肘部屈曲活动范围内移动，并在终点尽可能急剧地停止。一个电磁体，设置为每个受试者最大等长扭矩的0%、40%和70%，为运动起始提供阻力并导致快速释放运动。从肱二头肌和肱三头肌采集表面肌电图。结果表明，在所有条件下，男性的运动和加速度都更快。肌电图记录表明，男性的肌电图上升速率更快，特别是在肱三头肌，并且相互激活的耦合更紧密。快速释放使两组的加速度都更快，但只有男性在整个运动范围内移动得更快。在快速释放后，男性与女性的不同之处在于肱三头肌肌电图振幅增加。因此，男性能够通过增加肱三头肌的激活，从而提高制动能力，来缩短快速释放运动中的运动时间。这些结果表明，在肱三头肌快速肌电图激活方面，女性比男性在神经方面受到更多限制，导致制动过程受限。
