Burke D, Schiller H H
J Neurol Neurosurg Psychiatry. 1976 Aug;39(8):729-41. doi: 10.1136/jnnp.39.8.729.
Using a single fibre EMG electrode the firing pattern of 46 motor units in the triceps surae has been studied during vibration of the Achilles tendon at frequencies of 25--200 Hz. Potentials activated in the tonic vibration reflex (TVR) were phase-locked to the vibration cycle but tended to become somewhat less so with continued vibration. The firing pattern of voluntarily activated motor units became locked to the waveform by the application of the vibrator. The discharges of 21 motor units were studied during low threshold (sub-M wave) tetanic stimulation of the tibial nerve at 25--100 Hz. No evidence was found of synchronization of potentials activated in the resulting tonic contraction. During weak voluntary contractions, stimulation also failed to regularize voluntarily activated motor units. The findings can be reconciled by postulating that, in normal man, vibration activates monosynaptic and polysynaptic pathways, the latter circuit being adequate to generate reflex contraction, while the former merely affects the temporal patterning of the motor outflow.
使用单纤维肌电图电极，研究了跟腱在25 - 200赫兹频率振动时，腓肠肌中46个运动单位的放电模式。在紧张性振动反射（TVR）中激活的电位与振动周期锁相，但随着持续振动，这种锁相趋势会有所减弱。通过使用振动器，自主激活的运动单位的放电模式与波形锁定。在25 - 100赫兹对胫神经进行低阈值（亚M波）强直刺激期间，研究了21个运动单位的放电情况。未发现强直收缩中激活的电位有同步的证据。在微弱的自主收缩期间，刺激也未能使自主激活的运动单位放电规律化。这些发现可以通过假设来解释，即在正常人体中，振动激活单突触和多突触通路，后者足以产生反射性收缩，而前者仅影响运动输出的时间模式。
