RESPONSES OF HUMAN MUSCLE-SPINDLE ENDINGS TO VIBRATION DURING ISOMETRIC CONTRACTION
RESPONSES OF HUMAN MUSCLE-SPINDLE ENDINGS TO VIBRATION DURING ISOMETRIC CONTRACTION
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DOI：
10.1113/jphysiol.1976.sp011581
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发表时间：
1976-01-01
影响因子：
5.5
通讯作者：
WALLIN, BG
中科院分区：
文献类型：
--
作者：
BURKE, D;HAGBARTH, KE;WALLIN, BG
在人类受试者中，振幅为1.5 mm，频率为20-220 Hz的振动被施加到腿部肌肉的肌腱上，以检查在设计用于改变梭动驱动水平的动作期间对初级和次级末梢放电的影响。在4个实验中，在记录部位近端用利多卡因完全阻断腓总神经，以暂时传出梭形末梢。在多单元记录和单单元记录中看到的对肌肉拉伸和振动的反应在块期间与块之前的放松中相似。因此，这些实验没有提供功能有效的静息梭动驱动的证据。本文观察了9条初级终末和4条次级终末等长随意收缩时对振动的反应。如果末梢在放松状态下的反应次最大，则自主收缩增强了对振动的反应，这表明梭动系统的共同激活足以补偿机械卸载。卸载效应观察到相邻的协同肌肉收缩过程中，表明一个密切的空间关系之间的共同激活的骨骼运动和梭运动流出。在振动刺激引起的等长反射收缩（TVR收缩）期间，从10个初级末梢和7个次级末梢获得记录。对于12个末梢，强直性振动反射在受体轴承肌肉的外观导致振动的反应显着下降，这表明末梢被卸载的梭外收缩。在自愿抑制的反射收缩，纺锤体反应恢复到以前的水平。强直性振动反射，如腱反射，可以主要或专门作用于α。运动神经元，并且它可能不利用与自主收缩的表现中所使用的相同的皮质起源传出通路。
In human subjects, vibration of amplitude 1.5 mm and frequency 20-220 Hz was applied to the tendons of muscles in the leg to examine the effects on the discharge of primary and secondary endings during maneuvers designed to alter the level of fusimotor drive. In 4 experiments, the peroneal nerve was completely blocked with lidocaine proximal to the recording site in order to de-efferent spindle endings temporarily. The responses to muscle stretch and vibration, as seen in multi-unit recordings and in single unit recordings, were similar during the block as in the relaxed prior to the block. Thus, these experiments provided no evidence of a functionally effective resting fusimotor drive. The responses to vibration of 9 primary endings and 4 secondary endings were examined during isometric voluntary contractions of the receptor-bearing muscles. Provided that the endings were responding submaximally in the relaxed state, voluntary contraction enhanced the response to vibration, suggesting co-activation of the fusimotor system sufficient to compensate for mechanical unloading. Unloading effects were observed during contractions of neighboring synergistic muscles, indicating a close spatial relationship between the co-activated skeletomotor and fusimotor outflows. Recordings were obtained from 10 primary endings and 7 secondary endings during isometric reflex contractions resulting from the vibratory stimulus (TVR contractions). For 12 endings, the appearance of the tonic vibration reflex in the receptor-bearing muscle resulted in a significant decrease in the response to vibration, suggesting that the endings were unloaded by the extrafusal contraction. On voluntary suppression of the reflex contraction, spindle responses reverted to their previous levels. The tonic vibration reflex, like the tendon jerk reflex, may operate predominantly or exclusively on .alpha. motoneurons, and it may not utilize the same cortically originating efferent pathways as are used in the performance of voluntary contractions.