Citation

Graf M, Guggenbuhl U, Krueger H. Int. J. Ind. Ergonomics 1993; 12(1-2): 91-103.

Copyright

(Copyright © 1993, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

An investigation was undertaken to determine whether it was possible to achieve equivalent or greater postural improvement, in terms of spinal posture, positional variety and comfort, on a traditional chair modified by design changes to the seat surface to that of a forward sloping chair. Forward sloping chairs have the disadvantage that the body tends to slide forwards off the seat and the possibilities for position change are limited in that leaning backwards is awkward. Theoretically a chair should support a variety of body positions thus allowing the relaxation of alternate groups of muscles (encouraging dynamic seating behaviour). The modified design retains the traditional slightly concave surface for the area under the ischial tuberosities but the front 18 cm is angled downward. Results were obtained using a measuring technique which incorporates the dynamic movement patterns of working people. They indicate that the modified form can be used to achieve similar postural changes to the traditional form when sloped forwards for both assembly work and VDU work. Additionally a wider range of seating positions is adopted on it. Although forward thrust was not reduced the design was rated as more comfortable. This raised questions about whether discomfort is directly related to forward thrust. The issue of table height was also raised.