A longitudinal study of low-back pain as associated with occupational weight lifting factors.

A review of the biomechanics of weight lifting as it relates to low-back stresses is presented first. This serves as the basis for the development of a Lifting Strength Rating (LSR) methodology. Then a study is reported wherein the LSR methodology is used to evaluate 103 jobs having various amounts of required two-handed load lifting. The 411 people populating these jobs were also evaluated. For a period of one year following their evaluation, any low-back pain problems in the group were noted. The primary result of the field study is that the incidence rate of low-back pain is correlated with higher lifting strength requirements as determined by assessment of both the location and magnitude of the load lifted. It is, therefore, recommended that load lifting be considered potentially hazardous, and that the LSR methodology be used to guide corrective actions.