A Comparison of Four Methods Commonly Used to Determine Low-Back Disorder Risk in a Manufacturing Environment

Abstract

Manual material lifting is a major risk factor for work-related low back disorders (LBD's). Several methods for quantifying the specific aspects of lifting which are believed to contribute to LBD's have been developed and are beginning to be used in industry for job evaluation and re-design. The optimal method for determining the risk of occupational LBD on a population basis has not been determined. This study compared four evaluation methods used to assess occupational LBD risk in manual material handling tasks. The job evaluation methods examined were: the 1993 NIOSH model, the UAW-GM Ergonomic Risk Factor Checklist, the Static Strength Prediction Model, and the Lumbar Motion Monitor (LMM) model. The four methods were selected because they represent either common practice within the automotive industry, the result of governmental efforts to protect the work force, or models thought to be the most scientifically advanced. The analysis presented here was based on a random sample of production jobs in an automotive metal fabricating plant. The study population was comprised of automotive workers who perform materials handling operations. The sixty two jobs were all performed by three or more full time employees. Inter-correlations between measures were computed. In general, the inter-correlations while statistically significant (p<.05) were low (r < .42). This indicates that the different measures are most likely assessing different aspects of the work process.