ABSTRACT
Work seats must promote postural changes yet facilitate task demands. Frequently in such situations, the combination of a horizontal work surface with seat and reach constraints renders the back rest unusable. Although it is generally believed that a conventional seat can accommodate many people who work at a desk, Mandal has pointed out that forward postures at a horizontal surface introduce considerable loads on the spine. The possibility of using a narrow seat at some 20 cm higher than the deeper seat will be noted; several high work seats have been built to this dimension, resulting in a 'perch' for their users. If the demands of the task and work-place constrain the use of the work seat, every effort must be made to promote postural change. Many workers must choose between perching on the front of the seat, or standing, particularly where the work surface is high and/or restricts knee placement.
