Pope-Ford Regina, Jiang Zongliang
Industrial and Manufacturing Engineering and Technology Department, Bradley University, Peoria, IL, USA.
The Ergonomics and Biomechanics Laboratory, Department of Industrial and Systems Engineering, North Carolina A&T State University, Greensboro, NC, USA.
Work. 2015;51(3):391-9. doi: 10.3233/WOR-141883.
Dental practitioners often suffer musculoskeletal disorders (MSDs) in the upper extremity due to the static, repetitive and precise nature of work. Knowledge regarding muscle activation patterns in that region is essential in understanding the mechanism behind the upper extremity MSDs. However, the literature review has revealed few studies with such a focus.
This study aims to examine the inter-relationship of the exertion levels of eleven upper extremity muscles during common dental procedures. This provides insights into the interactive utilization patterns of the targeted muscles and their implications in the development of MSDs.
Twelve dentists were recruited. Electromyography (EMG) signals of sampled muscles were collected for 32 trials, i.e. combinations of independent variables (IVs) (and levels): posture (2), precision (2), line of vision (4), and grip type (2). Multivariate statistical methods were used to analyze the effects of IVs on muscle coactivity patterns.
MANOVA showed significant main effects and a 2-way interaction between precision and grip type. Most notably, the upper trapezius exhibited consistently higher utilization than other muscles during a seated posture.
Seated postures, preferred by dentists as a way to relieve back stress, may contribute to the development of shoulder or neck MSDs due to elevated upper trapezius exertions.
由于工作的静态、重复性和精确性，牙科从业者上肢常患肌肉骨骼疾病（MSD）。了解该区域的肌肉激活模式对于理解上肢MSD背后的机制至关重要。然而，文献综述显示，很少有研究关注这一点。
本研究旨在探讨常见牙科操作过程中11块上肢肌肉用力水平之间的相互关系。这有助于深入了解目标肌肉的交互使用模式及其在MSD发展中的影响。
招募了12名牙医。针对32种试验（即自变量（IV）及其水平的组合：姿势（2种）、精细度（2种）、视线方向（4种）和握持类型（2种））收集采样肌肉的肌电图（EMG）信号。采用多元统计方法分析自变量对肌肉共同激活模式的影响。
多变量方差分析显示了显著的主效应以及精细度和握持类型之间的双向交互作用。最值得注意的是，在坐姿时，上斜方肌的使用率始终高于其他肌肉。
牙医偏好的坐姿作为缓解背部压力的一种方式，可能由于上斜方肌用力增加而导致肩部或颈部MSD的发生。
