An experimental investigation of the quantitative effects of postural support on man's systemic stress mechanism during sustained visual task performance

The primary aim of this investigation was to examine experimentally the systemic stress effects produced by systems used to support the body in sedentary tasks. In the main experiment subjects were required to carry out a simple reading and writing task, for three hours, under two conditions. In one (T1) condition subjects were provided with a sedentary support and work surface arrangement which represented an average, dimensionally, of those found in offices. In the other condition (T2) a sedentary support-work surface configuration was individually fitted to each subject in conformity with ergonomics principles. The effects of the treatments were compared using the following: (a) biochemical responses, including total white cell and eosinophil blood counts, and urinary corticosteroid determinations; (b) visual and postural behaviour; (c) subjective comfort response; and (d) performance at the reading and writing task. [Continues.]