Department of Physical Therapy, College of Health and Medical Sciences, Cheongju University, Cheongju 28503, Korea.
Department of Dental Hygiene, College of Health and Medical Sciences, Cheongju University, Cheongju 28503, Korea.
Int J Environ Res Public Health. 2020 Nov 16;17(22):8494. doi: 10.3390/ijerph17228494.
The incidence of work-related musculoskeletal disorders (MSDs) among dental workers has been increasing. Many ergonomic devices and accessories have been introduced. The aim of this study was to investigate the effects of an 8-figure shoulder brace on posture-related muscle activities in dental hygiene practitioners during scaling procedures. In this study, 33 participants (age: 21.9 ± 2.1 years, height: 162.0 ± 6.0 cm, weight: 55.8 ± 9.0 kg, body mass index: 21.2 ± 2.4 kg/m) performed the scaling procedure with and without the 8-figure shoulder brace in a randomized order. The normalized electromyography activity in the amplitude probability distribution function and joint angles (cervical, thoracic, lumbar, and shoulder joints) were simultaneously recorded during scaling. A paired test was used to compare the differences in muscle kinematics, with the alpha level set at 0.05. The dental hygienists who wore the 8-figure shoulder brace during scaling showed thoracic and lumbar extension, improved sitting postures, and reduced shoulder joint abduction. However, we also observed an unintended increase in internal rotation. Use of the 8-figure shoulder brace could prevent work-related MSDs in lumbar and thoracic regions by reducing the effort exerted by the upper trapezius and deltoid muscles, despite the increased muscular effort of the cervical erector spinae.
牙科工作者中与工作相关的肌肉骨骼疾病（MSD）的发病率一直在上升。许多人体工程学设备和配件已经问世。本研究旨在探讨 8 字形肩部支撑带在洁牙过程中对牙科卫生从业人员姿势相关肌肉活动的影响。在这项研究中，33 名参与者（年龄：21.9±2.1 岁，身高：162.0±6.0cm，体重：55.8±9.0kg，体重指数：21.2±2.4kg/m）以随机顺序分别在使用和不使用 8 字形肩部支撑带的情况下进行洁牙操作。在洁牙过程中，同时记录幅度概率分布函数和关节角度（颈椎、胸椎、腰椎和肩关节）的归一化肌电图活动。使用配对 t 检验比较肌肉运动学的差异，显著性水平设为 0.05。在洁牙过程中佩戴 8 字形肩部支撑带的牙科保健员表现出胸椎和腰椎伸展，改善坐姿，并减少肩关节外展。然而，我们还观察到意外的内旋增加。尽管颈椎竖脊肌的肌肉用力增加，但 8 字形肩部支撑带的使用可以通过减少上斜方肌和三角肌的用力来预防腰椎和胸椎区域的与工作相关的 MSD。
