MOTOR-UNIT RECRUITMENT IN HUMAN 1ST DORSAL INTEROSSEOUS MUSCLE FOR STATIC CONTRACTIONS IN 3 DIFFERENT DIRECTIONS
MOTOR-UNIT RECRUITMENT IN HUMAN 1ST DORSAL INTEROSSEOUS MUSCLE FOR STATIC CONTRACTIONS IN 3 DIFFERENT DIRECTIONS
复制标题
DOI：
10.1152/jn.1986.55.5.1017
复制
发表时间：
1986-05-01
影响因子：
2.5
通讯作者：
STEIN, RB
中科院分区：
文献类型：
--
作者：
THOMAS, CK;ROSS, BH;STEIN, RB
采用棘波触发平均法提取4名受试者第一骨间背侧肌144个运动单位在食指外展、食指屈曲、拇指内收与食指屈曲三个不同静态收缩方向的抽动张力和收缩时间(以下简称内收)。虽然外展收缩的抽动张力通常最大，但所有单位都对所有三个方向的收缩都产生了张力。运动单位的抽动张力与静态收缩的三个方向呈线性相关。在每个方向上，这些运动单位的收缩张力与阈值力量之间也存在线性相关，这表明，根据抽动大小的增加，有序的募集模式足以描述人类第一骨间背侧肌在所有收缩方向的功能。没有明确的证据表明，在不同的任务中，肌肉中的不同组的运动单位被选择性地激活。运动单位在三个收缩方向上的招募等级顺序是相关的，但不是相同的。我们的数据的分散性与早期关于运动单位招募在不同运动中发生变化的报道有关。
Spike-triggered averaging was used to extract the twitch tensions and contraction times of 144 motor units from the first dorsal interosseous muscle of four subjects for three different directions of static contraction: abduction of the index finger, flexion of the index finger, and adduction of the thumb coupled with flexion of the index finger (hereafter referred to as adduction). Although the twitch tensions were generally largest for the abduction contraction, all units contributed tension to all three directions of contraction. A linear correlation was found for twitch tensions of motor units for the three directions of static contractions. Linear correlations were also found between twitch tension and threshold force of these motor units for each direction, which suggests that an orderly pattern of recruitment, according to increasing twitch size, adequately describes the function of human first dorsal interosseous muscle for all contraction directions. No clear evidence was found for separate groups of motor units in the muscle that were selectively activated for the different tasks. Rank order of recruitment for motor units in the three directions of contraction was correlated, but was not identical. The scatter in our data is discussed in relation to earlier reports of altered motor-unit recruitment during different movements.