An application of psychophysical ratings to external force estimation

An estimation of external force applied during hand-intensive work at actual work site has practical restrictions since direct measurement requires much equipment and time. This paper proposes a method that can estimate external forces applied at actual working environment on the basis of results of lab experiment. The psychophysical rating, specifically CR-10 scale developed by G. Borg, is adopted as the major tool to estimate external forces. This study also shows the general shape of the external force distribution for the most oommon and potentially risky hand postures of hand-intensive jobs.