The Measurement of Spinal Loads Arising from Working Seats

The backrest on a working seat reduces back muscle tension and the need to lock the spine for the transmission of horizontal forces from the trunk to the chair. These effects reduce inter-vertebral compression forces, which cause the discs to collapse. A simple and precise method for measuring shrinkage in stature has been developed and used to examine variations in the design of seats. The findings are discussed in relation to the biomechanics of sitting, and conclusions for seat design presented.