The revisions of the lifting equation used by NIOSH in an effort to assist in the analysis and prevention of back injuries caused by manual lifting reflected new findings and provided methods for evaluating asymmetrical lifting tasks and lifts of objects with less than optimal couplings between the object and the hands of the person doing the lifting. The revised equation also provided guidelines for a more diverse range of lifting tasks than did the earlier equation. The equation was only one tool of several to be used in a comprehensive effort to prevent work related low back pain and disability. The equation was discussed through a definition of the terms used, the limitations of the lifting task, the various components of the equation (horizontal, vertical, distance, asymmetry, frequency, and coupling), and the lifting index. Procedures were described for analyzing lifting jobs. Several example problems were considered, including jobs performed a few times per shift such as loading punch press stock, loading supply rolls, and loading bags into a hopper; single tasks performed repetitively such as package inspection and dish washing machine unloading; repetitive multitasks of short duration including a depalletizing operation and handling cans of liquid; and repetitive multitasks of long duration such as product packaging and warehouse order filling. A reprint of an article on the revised NIOSH equation was included in an appendix.