Influence of different stool types on muscle activity and lumbar posture among dentists during a simulated dental screening task

Abstract

Whereas in the past dental stools typically facilitated a 90° hip angle, a number of currently available alternative designs allow for a more extended hip posture. The present study investigated the influence of different stool types on muscle activity and lumbar posture. Twenty five participants completed a simulated dental procedure on a standard stool, a saddle and the Ghopec. The latter stool comprises a seat pan consisting of a horizontal rear part for the pelvis and an inclinable sloping down front part for the upper legs, with a vertically and horizontally adjustable back rest. Lumbar posture was most close to neutral on the Ghopec, whereas sitting on a standard/saddle stool resulted in more flexed/extended postures respectively. Sitting with a 90° angle (standard stool) resulted in higher activation of back muscles while sitting with a 125° angle (saddle and Ghopec) activated abdominal muscles more, although less in the presence of a backrest (Ghopec). To maintain neutral posture during dental screening, the Ghopec is considered the most suitable design for the tasks undertaken.

Biomechanical study of dentists posture when using a conventional chair versus a saddle-seat chair

“…21 Others studied lumbar posture in three different dental chairs during a dental task, and showed that the pelvis was in a more flexed position on a conventional seat compared with a saddle seat. 22 This study revealed similar results when dentists were working on the lower jaw. The use of a saddle seat results in a more lordotic posture due to the anteversion of the pelvis.…”

The role of ergonomic saddle seats and magnification loupes in the prevention of musculoskeletal disorders. A systematic review

“…This device measures the deviation of the spine from the neutral lumbar spine sitting posture, without taking into consideration the positioning of the upper limbs and neck. The findings of this study demonstrated that the participant dentists adopted a more favourable posture when seated in the saddle seats . In contrast, when they used the conventional seats, their posture was significantly more flexed and deviant from the neutral spinal posture .…”

“…From the included studies, 4 investigated the effect of loupes on posture and musculoskeletal pain, 4 the effect of saddle seats on posture and one of the latter explored the combined effect of magnification and use of a saddle seat on posture. The main characteristics of the included studies are summarized in Table , and the consensus ratings for the quality assessment (each domain and global judgement) of all studies are presented in Table .…”

“…Two of the studies evaluated the Salli ™ saddle seat and the other 2 the Bambach ™ seat . All of the studies explored the impact of the seats on posture, but none investigated their impact on musculoskeletal pain or incidence of MSDs.…”

“…Finally, De Bruyne et al, in a randomized within‐subjects study, used a wireless device (BodyGuard ™ ) to evaluate the spinal posture of a convenient sample of dentists and dental students while performing a simulated dental screening task on a phantom head. This device measures the deviation of the spine from the neutral lumbar spine sitting posture, without taking into consideration the positioning of the upper limbs and neck.…”