Diagnosis and Treatment Division, Nagura Orthopedic Clinic, Chuo, Tokyo, Japan.
Department of Orthopaedic Surgery, Keio University School of Medicine, Shinjuku, Tokyo, Japan.
BMC Musculoskelet Disord. 2022 Jul 14;23(1):669. doi: 10.1186/s12891-022-05623-z.
A small, wearable thermo device that uses Peltier elements for programmed heat and cold stimulation has been developed recently and is expected to be applied in conventional contrast bath therapy. This study was aimed to examine improvements in trapezius muscle hardness and subjective symptoms resulting from alternating heat and cold stimulation, with different rates of cooling.
This cross-over study included four conditions. Twenty healthy young male individuals (age, 22.3 ± 4.5 years) participated in this study. These four interventions targeted the unilateral trapezius muscle of the dominant arm after a 15-min typing task. Specifically, heat and cold stimulations were applied at different ratios (the heating/cooling rate of 3:1, 3:2, and 3:3) or not applied. Each intervention was separated by at least one week. Skin temperature at the stimulation area was recorded using a data logger. Outcome measures included muscle hardness (measured using a portable tester) and subjective symptoms (muscle stiffness and fatigue). Each item was assessed at three time points: baseline, after typing, and after the intervention.
Two-way analysis of variance with repeated measures found an interaction effect for muscle hardness between four conditions (3:1, 3:2, 3:3, and no) and three time points (p < 0.05). Only in the 3:1 condition were the post-intervention values lower than those after typing (p < 0.01). There was also an interaction effect for subjective muscle stiffness (p < 0.05); the values after the intervention in the 3:1 condition were lower than those after intervention in the no stimulation condition (p < 0.01). There was no significant relationship between changes in muscle hardness and changes in subjective symptoms in the 3:1 condition.
Our results demonstrate that alternating heat and cold stimulations with a different cooling rate could affect the degree of improvement in muscle hardness and subjective symptoms. In particular, the 3:1 condition has the possibility to improved muscle hardness within the condition and subjective muscle stiffness between conditions.
UMIN000040620. Registered 1 June 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359.
最近开发了一种小型可穿戴热设备，该设备使用珀耳帖元件进行编程热和冷刺激，预计将应用于常规对比浴治疗。本研究旨在检查不同冷却速率的冷热刺激对斜方肌硬度和主观症状的改善。
这项交叉研究包括四种情况。20 名健康年轻男性（年龄 22.3±4.5 岁）参与了这项研究。这四种干预措施针对优势臂的单侧斜方肌，在 15 分钟打字任务后进行。具体来说，在不同比例（加热/冷却率为 3:1、3:2 和 3:3）下应用或不应用加热和冷却刺激。每种干预措施之间至少间隔一周。使用数据记录器记录刺激区域的皮肤温度。测量指标包括肌肉硬度（使用便携式测试仪测量）和主观症状（肌肉僵硬和疲劳）。每个项目在三个时间点进行评估：基线、打字后和干预后。
重复测量的双向方差分析发现，四种条件（3:1、3:2、3:3 和无）和三个时间点（p<0.05）之间的肌肉硬度存在交互效应。只有在 3:1 条件下，干预后的数值低于打字后的数值（p<0.01）。主观肌肉僵硬也存在交互效应（p<0.05）；在 3:1 条件下的干预后数值低于无刺激条件下的干预后数值（p<0.01）。在 3:1 条件下，肌肉硬度的变化与主观症状的变化之间没有显著关系。
我们的结果表明，不同冷却速率的冷热交替刺激可能会影响肌肉硬度和主观症状改善的程度。特别是在 3:1 条件下，有可能在该条件下改善肌肉硬度和在条件之间改善主观肌肉僵硬。
UMIN000040620。于 2020 年 6 月 1 日注册，https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359。
