THE EFFECTS OF COMPUTER-INTERFACE DESIGN ON HUMAN POSTURAL DYNAMICS

The main objective of this study was to examine the effects of human-c omputer interface design on postural dynamics, i.e., changes in workin g postures and postural discomfort exhibited by operators of the compu ter-based remote bar coding (RBC) system. In addition, the effects of different work/rest schedules on postural dynamics were evaluated. Twe lve subjects participated in the laboratory experiment, which consiste d of twelve scenarios utilizing two cognitive task requirement factors , i.e., (1) information presentation mode, defined through the letter image preview on the computer screen (none or one preview image); and (2) the information processing mode, defined through the specific keyi ng method (key all characters or key 5 digits only). The third experim ental factor was the work/rest schedule (50 min work/10 min break, 2h of work/15 min break, or flexible schedule). The results showed that r equirements of human-computer interface design significantly affected the operators' postural dynamics. It was concluded that not only the p hysical, organizational, or psychosocial work environment characterist ics, but also the cognitive task characteristics are important for ass essment of postural effects in the VDT work. The relationship between interface design, mental workload and postural dynamics should be care fully considered in future studies aimed at optimizing the human-compu ter data entry tasks.