ABSTRACT

Repetitive peripheral magnetic stimulation (rPMS) is a non-invasive stimulator that can induce strong muscle contraction in selective regions. This study aimed to measure acute changes in skeletal muscle thickness induced by rPMS following a low-intensity exercise. Fifteen healthy young men performed an isometric knee extensor exercise at 30% of maximum strength consisting of three sets of 10 contractions on their dominant leg. rPMS was then applied on the vastus lateralis (VL) at the maximum intensity of the rPMS device. Muscle thicknesses of the rectus femoris (RF) and VL were measured using an ultrasound device and were compared among baseline, post-exercise, and post-rPMS. There were significant increases in muscle thickness of both the RF and VL post-exercise compared with baseline values (RF: baseline; 24.7 ± 2.4, post-exercise; 25.3 ± 2.4 mm, p = .034, VL: baseline; 27.0 ± 2.8, post-exercise; 27.4 ± 2.8 mm, p = .006). Compared with post-exercise, there was a significant increase post-rPMS in only the VL (VL: post-rPMS; 28.3 ± 2.9 mm, p = .002). These findings suggest that low-intensity isometric exercise can induce acute increases in muscle thickness (muscle swelling) in synergist muscles, and rPMS following exercise can induce further acute muscle swelling via repetitive muscle contraction.

摘要

重复外周磁刺激 (rPMS) 是一种非侵入性刺激器，可以在选择性区域诱导强烈的肌肉收缩。本研究旨在测量低强度运动后由 rPMS 引起的骨骼肌厚度的急性变化。15 名健康的年轻男性以最大力量的 30% 进行等长伸膝运动，包括三组 10 次收缩的优势腿。然后以 rPMS 装置的最大强度将 rPMS 应用于股外侧肌 (VL)。使用超声设备测量股直肌 (RF) 和 VL 的肌肉厚度，并在基线、运动后和 rPMS 后进行比较。与基线值相比，RF 和 VL 运动后的肌肉厚度均显着增加（RF：基线；24.7 ± 2.4，运动后；25.3 ± 2。p = .034，VL：基线；27.0 ± 2.8，运动后；27.4 ± 2.8 毫米，p = .006）。与运动后相比，rPMS 后仅 VL 显着增加（VL：rPMS 后；28.3 ± 2.9 毫米，p = .002）。这些研究结果表明，低强度等长运动会导致协同肌肉的肌肉厚度急剧增加（肌肉肿胀），运动后的 rPMS 可以通过重复肌肉收缩引起进一步的急性肌肉肿胀。