A posture and load sampling approach to determining low-back pain risk in occupational settings

A posture and load sampling approach to measure physical exposures was impl emented within a case-control study of low-back pain reporting. The purpose of this paper was to determine how well this method was able to identify k nown low-back pain risk factors. Subjects, including both cyclic production and non-cyclic support workers, were studied while working in an automotiv e assembly facility. The study included 104 (with 20 proxies) cases, worker s who reported low-back pain at work, and 129 randomly selected controls. R esults indicate significant associations between low-back pain reporting an d peak spinal loads (OR=2.0 for compression), shift-average spinal loading (OR=1.7 for compression), percent of lime with loads in the hand (OR = 1.5) , maximum flexion angle (OR = 2.2), and percent of time spent forward flexe d beyond 45 degrees (OR=1.3). Posture and hand load variables, considered t o be intermediate exposure variables, were handled separately in multivaria ble regression analyses from variables of peak and average spine force whic h directly estimate tissue loading. The work and posture sampling approach is particularly useful for heterogeneous work situations where traditional task analysis is difficult and can provide information on work and tissue l oad parameters which have been directly associated with risk of reporting l ow-back pain. Relevance to industry This paper demonstrates the effectiveness of an observational method in qua ntifying workplace exposures to physical risk factors for low-back pain. Th e method works for both cyclic and non-cyclic work. Quantified risk assessm ent provides key information for decision makers trying to control injury r ates in industrial systems. (C) 2001 Elsevier Science B.V. All rights reser ved.