AN ASSESSMENT OF SEATED ACTIVITY AND POSTURES AT 5 WORKPLACES

Static working positions and poor postures are both associated with th e development of musculo-skeletal disorders and discomfort. An assessm ent of people's postural behaviour requires suitable measurement tools and scales against which the measure can be judged. Although such met hods have been developed, these generally are aimed at assessing gross movements which are undertaken in an industrial setting where the wor kers are not sedentary. Seated workplaces are more the norm in modern societies and sedentary work does not provide immunity from discomfort and musculo-skeletal disorders. For this reason we have developed a m ethod for classifying and recording seated postural behaviour. This me thod is described along with the results of studies undertaken using t he method at five workplaces. The studies aimed to obtain some base da ta on sitting behaviour and how it related to work task and chair type . Postures were recorded at one-minute intervals during the subjects' normal work for periods up to two hours. Additionally, questionnaires regarding comfort and musculo-skeletal problems were issued to some of the subjects. Although individual variation was sizeable, the results showed clear postural behaviour differences between the various work tasks. Work tasks which have a higher incidence of musculo-skeletal di sorders were found to produce less frequent and less marked postural c hange. From these results some preliminary conclusions about an optima l seating behaviour pattern are made. Back disorders and discomfort ar e major sources of lost work time and worker dissatisfaction. Many of the problems can be traced back to poor seating or workplace design. T he paper elucidates postural behavioural factors which, along with the physical aspects of workplace furniture, affect people's comfort and well-being at work. These postural aspects are largely determined by t he work task.