Analysis of Subjective Body Discomfort Ratings during Simulated Prolonged Driving Tasks: What Measures are most Effective?

Abstract

Subjective discomfort ratings are a common assessment technique in human factors and ergonomics, and there exist a number of different methods for analyzing ratings (e.g., mean, median, maximum rating, etc.). The objective of this research was to evaluate multiple methods for analyzing body discomfort ratings. Perceived discomfort of eight participants was measured across ten body parts (buttock, left buttock, right buttock, lower back, upper back, neck, shoulder, eye, thigh and whole body) during 2-hour simulated driving tasks at 3 backrest angles (105°, 120°, 135°). Discomfort ratings were collected every 15 minutes using a modified Borg CR-scale. The time weighted discomfort (TWD) average of was found to be more sensitive to backrest angle changes than other measures considered. In addition, factor analysis revealed different methods provided different groupings of body parts, and the method selected for analyzing subjective discomfort ratings should be selected based on the objective of the study.