Occupational ergonomics. Theory and applications. Bhattacharya A, McGlothlin JD, eds. New York: Marcel Dekker, 1996 Apr; :627-653
Information is offered concerning the revised 1991 NIOSH lifting equation for assessing the physical demands of two handed manual lifting tasks. The revised equation included methods for evaluation of both symmetrical and asymmetrical lifting tasks, lifting objects with less than optimal coupling, and a wider range of lifting tasks than the 1983 equation. Discussion concerns what factors need to be measured, how they should be measured, what procedures should be used, and how the results can be used to ergonomically design new jobs or make decisions about redesigning existing jobs that may be hazardous. Definitions of several terms were provided, including recommended weight limit, measurement requirements, and lifting index. Various components of the data are discussed including the horizontal component, vertical component, distance component, asymmetry component, frequency component, and coupling component. Procedures to be used in analyzing a manual lifting job were described, included collecting the data, applying the equations, hazard assessment, and task redesign suggestions. Example problems considered included loading paper supply rolls, and dishwashing machine unloading.