Weerakkody N S, Blouin J S, Taylor J L, Gandevia S C
Prince of Wales Medical Research Institute, Barker Street, Randwick, Sydney, NSW 2031, Australia.
J Physiol. 2008 Jul 1;586(13):3183-93. doi: 10.1113/jphysiol.2008.152942. Epub 2008 May 8.
Activity in both muscle spindle endings and cutaneous stretch receptors contributes to the sensation of joint movement. The present experiments assessed whether muscle pain and subcutaneous pain distort proprioception in humans. The ability to detect the direction of passive movements at the interphalangeal joint of the thumb was measured when pain was induced experimentally in four sites: the flexor pollicis longus (FPL), the subcutaneous tissue overlying this muscle, the flexor carpi radialis (FCR) muscle and the subcutaneous tissue distal to the metacarpophalangeal joint of thumb. Tests were conducted when pain was at a similar subjective intensity. There was no significant difference in the ability to detect flexion or extension under any painful or non-painful condition. The detection of movement was significantly impaired when pain was induced in the FPL muscle, but pain in the FCR, a nearby muscle that does not act on the thumb, had no effect. Subcutaneous pain also significantly impaired movement detection when initiated in skin overlying the thumb, but not in skin overlying the FPL muscle in the forearm. These findings suggest that while both muscle and skin pain can disturb the detection of the direction of movement, the impairment is site-specific and involves regions and tissues that have a proprioceptive role at the joint. Also, pain induced in FPL did not significantly increase the perceived size of the thumb. Proprioceptive mechanisms signalling perceived body size are less disturbed by a relevant muscle nociceptive input than those subserving movement detection. The results highlight the complex relationship between nociceptive inputs and their influence on proprioception and motor control.
肌梭末梢和皮肤拉伸感受器的活动都有助于产生关节运动的感觉。本实验评估了肌肉疼痛和皮下疼痛是否会扭曲人类的本体感觉。当在四个部位通过实验诱发疼痛时，测量了检测拇指指间关节被动运动方向的能力：拇长屈肌（FPL）、该肌肉上方的皮下组织、桡侧腕屈肌（FCR）以及拇指掌指关节远端的皮下组织。在疼痛主观强度相似时进行测试。在任何疼痛或非疼痛条件下，检测屈伸的能力没有显著差异。当在FPL肌肉中诱发疼痛时，运动检测能力显著受损，但在附近不作用于拇指的FCR肌肉中诱发疼痛则没有影响。当在拇指上方的皮肤中引发皮下疼痛时，也会显著损害运动检测，但在前臂FPL肌肉上方的皮肤中引发疼痛则不会。这些发现表明，虽然肌肉和皮肤疼痛都可能干扰运动方向的检测，但这种损害是部位特异性的，并且涉及在关节处具有本体感觉作用的区域和组织。此外，在FPL中诱发的疼痛并没有显著增加拇指的感知大小。与那些服务于运动检测的本体感觉机制相比，传达感知身体大小的本体感觉机制受相关肌肉伤害性输入的干扰较小。结果突出了伤害性输入与其对本体感觉和运动控制的影响之间的复杂关系。
