Single motor unit activity in relation to pulsatile motor output in human finger movements
Single motor unit activity in relation to pulsatile motor output in human finger movements
复制标题
与人类手指运动中脉动电机输出相关的单个运动单元活动
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
N. Kakuda
中科院分区：
文献类型：
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作者：
J. Wessberg;N. Kakuda
1当受试者在单个掌指关节处进行自愿屈曲和伸展手指运动时，用肌内金属丝电极记录了普通手指伸肌、浅手指屈肌和第一骨间背侧肌中的46个单个运动单位。2运动单元放电与8 - 10 Hz不连续性相关，这些不连续性先前已被证明是这些运动的特征。对与不连续性相关的单个运动单位活动的统计时域和频域分析表明，当肌肉是激动剂时，手指伸肌中的所有运动单位以及屈肌中除一个外的所有单位都表现出与关节加速度密切相关的放电的显著频率调制。另一方面，运动单位放电率不相关的频率的不连续性。当记录的肌肉是拮抗剂时，25个活性单位中有21个表现出类似的频率调制。3当角运动速度从4增加到25 deg s-1时，运动单元频率调制的强度增加。运动单位活动和加速度之间的峰值一致性平均增加了74%，在共同的手指伸肌单位。[4]这些发现排除了将不连续性归因于新招募的运动单位以大约8 - 10 Hz的频率放电的初步机制。相反，暗示了对激动剂和拮抗剂运动神经元池的连贯8 - 10 Hz输入。
1 Forty‐six single motor units in the common finger extensor, superficial finger flexor, and first dorsal interosseus muscles were recorded with intramuscular wire electrodes while subjects made voluntary flexion and extension finger movements at a single metacarpo‐phalangeal joint. 2 Motor unit firing was analysed in relation to the 8‐10 Hz discontinuities which previously have been shown to characterize these movements. Statistical time‐ and frequency‐domain analyses of the activity of individual motor units in relation to the discontinuities showed that when the muscle was the agonist, all motor units in the common finger extensor muscle, and all units except one in the flexor muscles exhibited significant frequency modulation of their discharge in close temporal association with the joint acceleration. On the other hand, motor unit firing rate was not related to the frequency of the discontinuities. When the muscle recorded from was the antagonist, 21 of the 25 active units exhibited a similar frequency modulation. 3 When angular movement velocity was increased from 4 to 25 deg s−1, the strength of motor unit frequency modulation increased. Peak coherence between motor unit activity and acceleration increased by 74 %, on average, in the common finger extensor units. 4 The findings rule out a tentative mechanism attributing the discontinuities to newly recruited motor units firing at circa 8‐10 Hz. Instead, a coherent 8‐10 Hz input to the agonist and antagonist motoneurone pools is implied.