ABSTRACT
The diversity in design approaches and design criteria provide different safe load recommendations for manual lifting. The psychophysical design approach has been used for low as well as high lifting frequencies, and there is some evidence to indicate that it may overestimate the lifting capabilities of individuals both at very low and very high lifting frequencies. This chapter presents manual lifting design data for two-handed lifting for both male and female industrial workers for a wide range of task conditions. The manual lifting capability of workers is significantly influenced by the lifting duration. The inability to stand upright influences manual lifting capacity. Asymmetrical lifting by 90° can reduce a person's lifting capability by 8.4% if the feet move, and by as much as 22% if the feet are not allowed to move. Careful manoeuvering increases the load holding time and reduces the lifting capability. The additional physical stress caused by the heat stress results in reduced manual lifting capabilities.
