The Combination of Different Ergonomic Supports during Dental Procedures Reduces the Muscle Activity of the Neck and Shoulder

Abstract

Ergonomic supports have become popular for the prevention of musculoskeletal disorders. This study sought to evaluate the efficacy of different ergonomic supports and their combination to reduce muscle activity of the neck and shoulder muscles. A one-way repeated measures design was used to evaluate 36 practicing dentists while they performed three posterior composite restoration procedures on a phantom head. Portable surface electromyography (sEMG) recordings were used to measure the muscle activity of three muscles (Upper Trapezius, Lateral Deltoid and Anterior Deltoid) in the dominant upper extremity, with and without the use of different ergonomic supports (ergonomic stool, magnification lenses and both) during the performance of these tasks. A repeated measures analysis of variance was used. The muscle activity of all muscles differed significantly across the four ergonomic conditions during the three tasks. The use of ergonomic supports such as magnification lenses, the ergonomic stool, or the combination of both, is effective for decreasing the muscle activity of the three muscles during the three tasks, when compared to standard practice. In addition, the decrease of muscle activity was higher using magnification lenses when compared to the ergonomic stool. Furthermore, the greatest decrease was found with the combination of both supports.

Using Electromyography to Assess Postural Load in Dentistry: A Literature Review

“…In addition to the dorsal part, the frontal part of the trunk and the neck were also evaluated. García-Vidal et al, [10] recorded EMG signals of the Upper Trapezius, Lateral Deltoid and Anterior Deltoid muscles in a study that verified the influence of different ergonomic supports (ergonomic dental stool and loupes) and their combination on the muscular activity of the dominant upper extremity. La Delfa et al, [30], in addition to the muscles already mentioned they also included m. cervical erector spinae and m. pectoralis major, to assess the biomechanical load in the neck and shoulder region during a 30minutes dental scaling, as well as the postural variations in the different dental work positions according to the imaginary clock.…”

“…This review revealed that most studies on the topic have used surface electromyography. Some authors have defended the use of this type of electromyography as it is a non-invasive, safe, reliable and easy-to-use method that allows objectively assessing responses to muscle stimulation [10,15,17,25,34].…”

“…In the studies found, it was observed that the dorsal trunk region was the most evaluated, with the trapezius muscle, both in its ascending and descending portion, being the most studied muscle [10,11,12,15,18,19,24,27,28,30,35]. Akesson et al, [18] used surface EMG for evaluation of the demands experienced by dental hygienist during their working routine, recording the descending part of the upper trapezius muscle bilaterally.…”

“…One region that apparently was not much explored was the abdominal (part of the frontal trunk) and lower body region. Although some studies have evaluated muscle activity related to sitting work [10,19,27,28,29], few considered this region [5,20,32,33]. De Bruyne et al, [5], evaluated the effect of 3 different types of dental stools on the muscular activity (EMG) of the m. latissimus dorsi, m. iliocostalis lumborum thoracic part, m. multifidus, m. gluteus maximus, m. rectus femoris, m. internal abdominal oblique and m. external abdominal oblique.…”

“…A direct assessment method that has been used in several areas of dentistry is electromyography, a non-invasive method that allows the assessment of the neuromuscular system [8]. This tool is widely used to assess the physiology of masticatory muscles [9] and has also been gaining space in the operator's postural assessment during his clinical practice [10]. However, there are few studies in the literature that evaluate the benefits and limitations of the use of electromyography in the evaluation of the ergonomic posture of dentists.…”