Schlenker Anna, Kapitán Martin, Vavřičková Lenka, Bušová Milena
Institute of Hygiene and Epidemiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
Department of Dentistry, Faculty of Medicine in Hradec Kralove, Charles University and University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.
Cent Eur J Public Health. 2020 Oct;28 Suppl:S12-S16. doi: 10.21101/cejph.a6157.
Hands and forearms are one of the most common localisations of musculoskeletal disorders (MSDs) among dental practitioners. The aim of this study was to objectively assess the local muscular load of hands and forearms of dental practitioners during various treatment procedures using the method of the integrated electromyography (iEMG). This method is used for health risk assessment and categorization of working operation within the official national methodology.
A total of 24 measurements were performed on 10 dental practitioners during 8 different dental treatments; mostly on those which are most frequent in clinical practice, i.e. endodontic treatment, tooth extraction, tooth restoration with filling and prosthetic treatment. The EMG Holter was used to detect the electromyographic potentials determining the local muscular load.
All the muscle groups of the forearm were relatively evenly loaded at work. During the dynamic work activity, the average time-weighted value of maximum voluntary contraction (%MVC) was in the range from 1 to 30 %MVC for all evaluated muscle groups. The mean average time-weighted value of %MVC did not exceed 6% (a critical limit of the mean average time-weighted value of %MVC) in any of the evaluated muscle groups. The results of the frequency analysis showed that large (55-70 %MVC) and rarely the limits exceeding values (above 70 %MVC) were observed for individual muscle groups. These forces are related to performing tasks at inaccessible locations associated with non-physiological working positions. The differences in the mean forearm muscle load between the upper limbs were statistically significant in total (p < 0.001), for flexors (p = 0.017) and for extensors (p = 0.006).
In view of the results of this study, the work of dentists can be ranked in category 2 in terms of the local muscle load factor according to the currently valid legislation in the Czech Republic.
手和前臂是牙科从业者中肌肉骨骼疾病（MSD）最常见的发病部位之一。本研究的目的是使用集成肌电图（iEMG）方法客观评估牙科从业者在各种治疗程序中手和前臂的局部肌肉负荷。该方法用于官方国家方法中的健康风险评估和工作操作分类。
在10名牙科从业者进行8种不同牙科治疗期间共进行了24次测量；主要针对临床实践中最常见的治疗，即牙髓治疗、拔牙、补牙修复和修复治疗。使用肌电图动态监测仪检测确定局部肌肉负荷的肌电电位。
工作时前臂的所有肌肉群负荷相对均匀。在动态工作活动期间，所有评估肌肉群的最大自主收缩平均时间加权值（%MVC）在1%至30%MVC范围内。在任何评估肌肉群中，%MVC的平均时间加权值均未超过6%（%MVC平均时间加权值的临界极限）。频率分析结果表明，个别肌肉群出现了较大的力（55 - 70%MVC），很少出现超过极限值的情况（高于70%MVC）。这些力与在难以触及的位置执行任务以及非生理性工作姿势有关。上肢之间前臂肌肉平均负荷的差异总体上具有统计学意义（p < 0.001），屈肌（p = 0.017）和伸肌（p = 0.006）也是如此。
根据本研究结果，按照捷克共和国现行有效立法，牙医的工作在局部肌肉负荷因素方面可归类为2类。
