Comparative study of the saddle chair with two other conventional types of chair on the risk of musculoskeletal disorders and perceived comfort in dentists

dentists often have to adopt awkward, asymmetric, static postures and tilt their heads forward while working. If this situation continues for a long time every day, it leads to excessive pressure on the involved muscles and joints and causes symptoms such as pain and discomfort, especially in the neck, shoulders, back, and waist. Considering the importance of prevention, and early treatment of musculoskeletal disorders among dentists, this research investigates the effect of three types of chairs used in dentistry on the risk of musculoskeletal disorders and the comfort perceived by dentists using each chair.

This is a descriptive cross-sectional study conveyed in Tehran, the capital city of Iran. The present study includes a survey of a group of 70 male dentists. In this study, three types of chairs were compared. To evaluate body comfort, Corlette, and Bishop’s local discomfort questionnaire was used. The RULA method was used to determine the risk of upper limb musculoskeletal disorders and to assess each dentist's body condition.

The highest level of comfort was reported in the saddle model chair (the difference in the average intensity of discomfort before and after the work shift in the whole body = 12.39), the third type chair (13.04), and the second type chair (18/76). The dentists' posture evaluation results showed that the final score of RULA in three types of chairs varies from a minimum of 3 to a maximum of 7.

According to the results of the study, the average intensity of discomfort in the whole body after using the saddle chair compared to the state before using it has significantly decreased compared to the other two types of chairs, which implies the positive effect of using the saddle chair in reducing musculoskeletal discomfort. The results of posture evaluation indicate that the use of the saddle chair, compared to the other two chairs, improves the working conditions and facilitates the work.