ABSTRACT
Early research in manual materials handling examined physiological, biomechanical and psychophysical capabilities of workers in standard lifting postures, which were usually described as two-handed, symmetric, sagittal plane lifting (or lowering). In 1981, NIOSH published Work Practices Guide for Manual Lifting which established recommended manual materials handling limits for such “standard postures.” In 1991, revisions to the guide were published in which angle of twist was one of the components added to the recommended weight limit calculation (Waters et al. 1994). However, more unusual postures have received little attention. Part of the obvious reason is that, by definition, unusual postures imply that the situation is unique and hence trying to establish norms for unique postures has limited value.
