Pantaleo Tito, Duranti Roberto, Bellini Fabrizio
Istituto Interfacoltà di Fisiologia Università degli Studi, 50134 FlorenceItaly Istituto di Clinica Medico III, Università degli Studi, 50134 FlorenceItaly.
Pain. 1986 Feb;24(2):239-250. doi: 10.1016/0304-3959(86)90046-1.
The effects of vibratory stimulation on muscular pain threshold were investigated in 28 healthy subjects. Pain sensation was evaluated by the subjects' verbal reports in response to electrical stimulation of the vastus medialis muscle. Concomitant variations of blink response evoked as a component of the startle reaction were also studied. In all the subjects tested, high frequency vibration (110 Hz) induced a marked and long lasting elevation of the muscular pain threshold but only when vibration was applied to the skin overlying the ipsilateral quadriceps tendon or neighbouring areas and not when applied to remote ipsi- or contralateral regions. This effect was prevented either when tonic vibration reflex (TVR) of the quadriceps muscle was elicited or the skin underlying the vibrator was anaesthetized. Vibratory stimulation at low frequency (30 Hz) failed to produce any consistent effect on muscular pain threshold. Variations in threshold for blink response, as a rule, closely followed those of muscular pain threshold. However, a facilitation of the blink response, not accompanied by changes in pain sensation, was observed during the first period of both high and low frequency vibratory stimulation. The effectiveness of high frequency vibration in raising the muscular pain threshold is coherent with previous results showing that vibration is able to affect pain sensation. Present results suggest a role for rapidly adapting receptors (RA) and/or pacinian corpuscles (PC) in this effect and support the hypothesis of an inhibition of nociceptive messages, possibly at spinal segmental levels, by volleys in large myelinated afferent fibres.
在28名健康受试者中研究了振动刺激对肌肉痛阈的影响。通过受试者对股内侧肌电刺激的口头报告来评估疼痛感觉。还研究了作为惊吓反应一部分诱发的眨眼反应的伴随变化。在所有测试的受试者中，高频振动（110Hz）可引起肌肉痛阈显著且持久的升高，但仅当振动施加于同侧股四头肌肌腱上方或邻近区域的皮肤时才会出现这种情况，而施加于同侧或对侧较远区域时则不会。当诱发股四头肌的紧张性振动反射（TVR）或麻醉振动器下方的皮肤时，这种效应会被阻止。低频（30Hz）振动刺激未能对肌肉痛阈产生任何一致的影响。通常，眨眼反应阈值的变化与肌肉痛阈的变化密切相关。然而，在高频和低频振动刺激的第一阶段，均观察到眨眼反应的易化，且疼痛感觉无变化。高频振动提高肌肉痛阈的有效性与先前表明振动能够影响疼痛感觉的结果一致。目前的结果表明快速适应性感受器（RA）和/或环层小体（PC）在这种效应中起作用，并支持在脊髓节段水平可能通过大的有髓传入纤维的冲动抑制伤害性信息的假说。
