主动运动和被动运动的镇痛效果及其镇痛机制

主动运动和被动运动可以有效缓解各种急性疼痛和慢性疼痛,且主动运动诱发的镇痛效果强于运动参数相似的被动运动.文章在讨论运动镇痛机制的基础上,探讨了主、被动运动镇痛效果存在差异的原因.具体来说,通过比较两种运动传导运动信息的下行通路和传导躯体感觉/本体感觉的上行通路,论述了主、被动运动在生理(外周神经系统和中枢神经系统)和心理(情绪和认知)层面上镇痛机制的异同.由于被动运动缺少运动下行控制且肌肉激活程度小,其在外周镇痛物质含量和皮层水平上对疼痛的调控弱于主动运动.此外,被动运动相比主动运动不易诱发积极情绪,较难转移对疼痛的注意力,缺乏身体掌控感并拥有较低的身体归属感,进而导致较弱的镇痛效果.最后,文章指出了目前本领域研究的局限性,并对运动镇痛未来的研究方向和方法提出了建议.

Analgesic Effects of Active Exercise and Passive Exercise and Their Mechanisms

Both active exercise and passive exercise are effective in reliving various acute and chronic pain. The analgesic effect induced by active exercise is more effective than that induced by passive exercise. Based on the discussion of the underlying mechanisms of exercise-induced analgesia, this review highlights the possible reasons that explain the differences between the two types of exercises in terms of their effectiveness. Specifically, by comparing the motor descending pathway and the somatosensory/proprioception ascending pathway between active exercise and passive exercise, the possible physiological (i.e., the peripheral nerve system and the central nerve system) and psychological (i.e., cognition and emotion) mechanisms involved in pain modulation between the two are fully discussed. Owing to a lack of the motor descending pathway and the limited muscle activation during the movement execution, passive exercise triggers less release of analgesic substances and a weaker pain modulation at cortical level, when compared with active exercise. In addition, passive exercise can barely evoke positive emotion or distract the attention away from pain. The lack of sense of agency and having less sense of ownership along with passive exercise further negatively affect the analgesic effect. Drawing upon the evidence, we point out the limitations of current studies in this field and suggest future research directions for a better understanding of exercise-induced analgesia.