The Effect of Arm Supports on Muscle Activity, Posture, and Discomfort in the Neck and Shoulder in Microscopic Dentistry: Results of a Pilot Study

Abstract

OCCUPATIONAL APPLICATIONS When arm supports are provided during endodontic work, the use of the arm supports reduces static and median neck/shoulder muscle activity but does not seem to affect peak muscle activity. In addition, providing arm supports reduces the time working with unsupported upper arm angles <60°, but does not affect the time working unsupported with upper arm angles >60°. These results illustrate that in dentistry work in general, and in endodontic work specifically, dentists should be encouraged not only to optimize but also use their work environment to effectively reduce their workload.TECHNICAL ABSTRACT Background: Endodontic dentists treat dental nerves and tissues by performing precision tasks using a microscope. Their work is associated with a high prevalence of musculoskeletal symptoms. Purpose: This study was conducted to investigate the effect of the availability and use of arm supports on neck and shoulder load during endodontic work. Methods: A group of 11 endodontists performed an endodontic task under three arm support conditions: (1) using flexible arm supports; (2) using fixed arm supports; and (3) without arm supports. Surface electromyography, posture, and self-reported discomfort in the neck and shoulders were assessed as outcome measures. Results: Use of arm supports reduced static and median neck/shoulder muscle activity, but did not affect peak muscle activity. The presence of arm supports reduced the relative time working unsupported with upper arm angles <60°, but did not affect the time working unsupported with upper arm angles >60° or self-reported discomfort. Conclusions: When arm supports are provided during endodontic work, their use decreases neck/shoulder muscle activity and reduces the time working with non-neutral postures of the upper extremities. However, the clinical relevance of these findings needs to be evaluated in longitudinal field studies.