PROBLEMS AND SOLUTIONS IN MANUAL MATERIALS HANDLING - THE STATE-OF-THE-ART

For several decades manual materials handling has been a topic of interest in many fields of research. The reason for this interest is the devastating cost of and human suffering caused by injuries associated with MMH. Prevention and control of these injuries has been a concern shared by many researchers. In order to control the nature and extent of these injuries, limits must be established for MMH, especially lifting. This paper summarizes the variables affecting the ability to handle materials and the three basic approaches to determining capacities and limits for MMH: the biomechanical, the physiological, and the psychophysical approaches. The paper presents the various models developed in each of these approaches, together with a discussion of progress made and difficulties encountered in deriving capacity recommendations from each. Finally, the paper presents the latest recommendation on how these approaches can be integrated into a single comprehensive model for establishing lifting limits.