Kang Jong Ho, Jeong Byeong Ho, Jang Jun Hyeok
Department of Physical Therapy, College of Health Sciences, Catholic University of Pusan.
J Phys Ther Sci. 2013 Jul;25(7):881-3. doi: 10.1589/jpts.25.881. Epub 2013 Aug 20.
[Purpose] The objective of this study was to propose a work environment that could reduce musculoskeletal workload. Accordingly, spinal muscle fatigue caused by ultrasound therapy at various treatment table heights was examined and compared. [Subjects and Methods] Twenty-five healthy subjects participated in this experiment. The table height was set to 100%, 125%, and 150% of the stool height (45 cm). The electromyographic signals of the erector spinae at the thoracic (T10, T12) and lumbar (L2, L4) levels were collected by an electromyography (EMG) system during the performance of ultrasound therapy. The median frequencies were then calculated and compared. [Results] The lower the table height was, the smaller the median frequencies of thoracic and lumbar erector spinae on both sides were. The T10 and T12 levels on both sides and the left L2 region showed significant differences among the table heights. At every spinal level, the median frequency of the left erector spinae was lower than that of the right: T10, T12, L2, and L4 at 100%, L4 at 125%, and T10, T12, L2, and L4 at 150% showed significant differences. [Conclusion] During ultrasound therapy muscle fatigue increased at higher table heights and the muscle fatigue of the left erector spinae was greater than that of the right side. To reduce muscle fatigue, we recommend the table height work is raised to an appropriate height, and that is shared between left and right arms.
[目的] 本研究的目的是提出一种可减轻肌肉骨骼工作量的工作环境。因此，对在不同治疗台高度进行超声治疗引起的脊柱肌肉疲劳进行了检查和比较。[对象与方法] 25名健康受试者参与了本实验。治疗台高度设置为凳子高度（45厘米）的100%、125%和150%。在进行超声治疗期间，通过肌电图（EMG）系统收集胸段（T10、T12）和腰段（L2、L4）竖脊肌的肌电信号。然后计算并比较中位频率。[结果] 治疗台高度越低，两侧胸段和腰段竖脊肌的中位频率越小。两侧的T10和T12水平以及左侧L2区域在不同治疗台高度之间存在显著差异。在每个脊柱水平，左侧竖脊肌的中位频率均低于右侧：100%时的T10、T12、L2和L4，125%时的L4，以及150%时的T10、T12、L2和L4均显示出显著差异。[结论] 在超声治疗期间，较高的治疗台高度会增加肌肉疲劳，且左侧竖脊肌的肌肉疲劳大于右侧。为减轻肌肉疲劳，我们建议将治疗台高度调整到合适高度，并在左右臂之间均匀分配工作。
