Effects of the Jendrassik manoeuvre on muscle spindle activity in man.
Effects of the Jendrassik manoeuvre on muscle spindle activity in man.
复制标题
Jendrassik 动作对人体肌梭活动的影响。
DOI：
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复制
发表时间：
1975
影响因子：
11
通讯作者：
L. Löfstedt
中科院分区：
文献类型：
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作者：
K. Hagbarth;G. Wallin;D. Burke;L. Löfstedt
从健康成年受试者的正中神经、腓神经和胫神经的肌神经束中采集了28个被鉴定为初级或次级纺锤体传入的机械感受单位。这些单位对持续的被动肌肉拉伸、被动拉伸运动、肌腱敲击和电诱导的肌肉抽搐的反应进行了研究，同时受试者在远处的肌肉群中进行重复的Jendrassik动作，包括强烈的自愿收缩。只要在受体承载的肌肉中没有出现无意收缩的肌电迹象，也没有机械换能器无意改变肌肉负荷的位置变化的迹象，动作就不会对传入纺锤放电产生影响。然而，在动作过程中，承载受体的肌肉经常发生无意的收缩，然后观察到纺锤体传入的共同激活。从胫神经束引出的跟腱敲击的多单位传入反应也以类似的方式不受Jendrassik动作的影响，即使这些动作导致小腿肌腱痉挛明显加强。结果没有证据表明Jendrassik动作期间保持放松的肌肉中的纺锤体被纺锤马达敏化，而反射强化在被测肌肉中没有伴随的主动张力升高的迹象被推测依赖于脊髓内传入截击的改变处理。
Twenty-eight mechanoreceptive units identified as primary or secondary spindle afferents were sampled from muscle nerve fascicles in the median, peroneal, and tibial nerves of healthy adult subjects. The responses of these units to sustained passive muscle stretch, to passive stretching movements, to tendon taps, and electrically-induced muscle twitches were studied while the subject performed repeated Jendrassik manoeuvres involving strong voluntary contractions in distant muscle groups. The manoeuvres had no effect upon the afferent spindle discharges as long as there were no EMG signs of unintentional contractions occurring in the receptor-bearing muscle and no mechanotransducer signs of unintentional positional changes altering the load on that muscle. Unintentional contractions in the receptor-bearing muscle frequently occurred during the manoeuvres, however, and then coactivation of the spindle afferents was observed. Multiunit afferent responses to Achilles tendon taps, led off from tibial nerve fascicles, were in a similar way uninfluenced by the Jendrassik manoeuvres, even when these resulted in marked reinforcement of the calf muscle tendon jerk. The results provide no evidence for fusimotor sensitization of spindles in muscles remaining relaxed during the Jendrassik manoeuvre, and reflex reinforcement occurring without concomitant signs of active tension rise in the muscles tested is presumed to depend upon altered processing of the afferent volleys within the cord.