A user-friendly three-dimensional kinetic model for analyzing manual lifting tasks

Abstract

Prevention of musculoskeletal disorders resulting from manual material handling tasks has been among the foremost concerns of industrial ergonomics researchers. Kromodihardjo and Mital (1986, 1987) contributed significantly to the research in this area by developing a 3-D kinetic model for the analysis of manual lifting. Kromodihardjo and Mital's model (K–M model), and other kinetic models, rely on explicit kinematic information of the tasks being performed. Thus, time variations of displacements, velocities and accelerations (both linear and angular) for all body joints have to be known beforehand in order to perform an analysis. This, in turn, requires experiments to be conducted with individual subjects each time an analysis is needed. This is a tedious procedure and deters the generic use of such models. The present work was, therefore, initiated with the objective of encapsulating the K–M model into a form which could be readily used and applied to industrial situations. A comparison of the results obtained with the simplified model with results from K–M model shows an excellent match. Relevance to industry A readily usable PC-based 3-D kinetic model to analyze symmetrical and asymmetrical manual lifting activities is presented. The model eliminates cumbersome data collection and data reduction requirements.