Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan.
J Electromyogr Kinesiol. 2010 Apr;20(2):290-7. doi: 10.1016/j.jelekin.2009.03.007. Epub 2009 Apr 16.
In this study, we investigated a motor strategy for increasing the amplitude of movement in rapid extensions at the elbow joint. This study focused on the changes in a triphasic electromyographic (EMG) pattern, i.e., the first agonist burst (AG1), the second agonist burst (AG2) and the antagonist burst (ANT), for increasing the amplitude of movement required after the initiation of movement. Subjects performed 40 degrees (Basic task) and 80 degrees of extension (Wide task). These tasks were performed under two conditions; performing a predetermined task (SF condition) and performing a task in response to a visual stimulus immediately after movement commencement (ST condition). Kinematic parameters and EMG activity from the agonist (triceps brachii) and the antagonist (biceps brachii) muscles were recorded. As a result, the onset latency of AG1 and AG2 and the duration of AG1 were longer under the ST condition than the SF condition. No difference was observed between the SF and ST condition with respect to ANT activity. It is concluded that the motor strategy for increasing the amplitude of movement after the initiation of movement was to control the movement velocity and the timing to stop movement by the coactivation duration of AG1 and ANT and to stop the desired position accurately by AG2 activity.
在这项研究中，我们研究了一种用于增加肘部快速伸展运动幅度的运动策略。本研究侧重于三相肌电图（EMG）模式的变化，即第一个激动剂爆发（AG1）、第二个激动剂爆发（AG2）和拮抗剂爆发（ANT），以增加运动开始后所需的运动幅度。受试者进行了 40 度（基础任务）和 80 度的伸展（宽任务）。这些任务在两种条件下进行；执行预定任务（SF 条件）和在运动开始后立即响应视觉刺激执行任务（ST 条件）。记录了来自 agonist（肱三头肌）和 antagonist（肱二头肌）肌肉的运动学参数和 EMG 活动。结果，在 ST 条件下，AG1 和 AG2 的起始潜伏期和 AG1 的持续时间比 SF 条件长。SF 和 ST 条件之间在 ANT 活动方面没有差异。结论是，运动策略是通过 AG1 和 ANT 的共同激活持续时间来控制运动速度和停止运动的时机，然后通过 AG2 活动来停止所需的位置，从而在运动开始后增加运动幅度。
