电刺激肌肉诱发的肌肉收缩对内源性疼痛调制系统的影响：一项定量感觉测试评估

Impact of electrical muscle stimulation-induced muscle contractions on endogenous pain modulatory system: a quantitative sensory testing evaluation.

作者信息

Ohga Satoshi, Hattori Takafumi, Shimo Kazuhiro, Maeda Hajime, Matsubara Takako

机构信息

Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, Hyogo, 651-2180, Japan.

Faculty of Rehabilitation, Kobe Gakuin University Graduate School, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, Hyogo, 651-2180, Japan.

出版信息

BMC Musculoskelet Disord. 2024 Dec 27;25(1):1077. doi: 10.1186/s12891-024-08154-x.

DOI:10.1186/s12891-024-08154-x

PMID:39731029

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11673366/

Abstract

BACKGROUND

Exercise-induced hypoalgesia (EIH) is characterized by a reduction in pain perception and sensitivity across both exercising and non-exercising body parts during and after a single bout of exercise. EIH is mediated through central and peripheral mechanisms; however, the specific effect of muscle contraction alone on EIH remains unclear. Moreover, previous studies on electrical muscle stimulation (EMS) have primarily focused on local analgesic effects, often relying on subjective pain reports. This study investigated the contribution of EMS-induced muscle contractions to systemic analgesia, independent of motor cortex activity. We aimed to explore the underlying mechanisms of EIH by analyzing the influence of skeletal muscle mass (SMM), skeletal muscle mass index (SMI), and conditioned pain modulation (CPM).

METHODS

In this crossover study, 27 healthy young adults participated in EMS and sham interventions, separated by a washout period of 2 to 3 days. SMM, SMI, and CPM were measured before the first intervention. Pressure pain thresholds (PPT) were evaluated before and after each intervention. EMS was applied to the non-dominant quadriceps at a frequency of 30 Hz, a pulse duration of 300 μs, and a duty cycle of 5 s on and 10 s off, without inducing joint movement, for 20 min. The sham intervention used the same settings, but the stimulation amplitude was insufficient to induce muscle contraction in the quadriceps. The average current intensity was 16.0 ± 3.2 mA and 11.3 ± 2.3 mA in the EMS and sham condition, respectively.

RESULTS

In the EMS condition, PPT significantly increased in the stimulated quadriceps but not in non-contracted sites. There were strong positive correlations between changes in PPT and both SMM and SMI, but not CPM. The sham condition showed no significant effects at any assessment sites.

CONCLUSIONS

These findings suggest that the analgesic effects of EMS-induced muscle contractions are primarily localized to the stimulated muscle tissues, rather than mediated by the central pain modulatory mechanisms.

TRIAL REGISTRATION

This study was enrolled in the UMIN-CTR Clinical Trial Registry (registration number: UMIN000051951; date of approval: August 19, 2023).

摘要

背景

运动诱导性痛觉减退（EIH）的特征是在单次运动期间及之后，运动和非运动身体部位的疼痛感知和敏感性均降低。EIH通过中枢和外周机制介导；然而，仅肌肉收缩对EIH的具体影响仍不清楚。此外，先前关于电肌肉刺激（EMS）的研究主要集中在局部镇痛作用，通常依赖主观疼痛报告。本研究调查了EMS诱导的肌肉收缩对全身镇痛的作用，独立于运动皮层活动。我们旨在通过分析骨骼肌质量（SMM）、骨骼肌质量指数（SMI）和条件性疼痛调制（CPM）的影响来探索EIH的潜在机制。

方法

在这项交叉研究中，27名健康年轻成年人参与了EMS和假干预，中间间隔2至3天的洗脱期。在第一次干预前测量SMM、SMI和CPM。在每次干预前后评估压力疼痛阈值（PPT）。将EMS以30Hz的频率、300μs的脉冲持续时间和5秒开启及10秒关闭的占空比施加于非优势股四头肌，不引起关节运动，持续20分钟。假干预使用相同设置，但刺激幅度不足以诱导股四头肌收缩。在EMS和假干预条件下，平均电流强度分别为16.0±3.2mA和11.3±2.3mA。