A psychophysical study of work-related stress using observer ratings.

In two experimental series a panel of observers rated the perceived exertion of a worker performing different tasks. The first experiment involved the lifting of boxes of different weights. The second experiment comprised combined static and dynamic work of the assembly-line type during a full working day. The results show that the observers were able to discriminate between the different loads in all stress situations. Since the loads ranged from low to maximal stress, all were able to make assessments over the full range. Furthermore, the relationship between observer ratings and self-ratings approximated a logarithmic function with the observers tending to overestimate the low stresses while there was closer agreement in the rating of high stresses.