Biomechanical and psychosocial risk factors for low back pain at work

Objectives. This study determined whether the physical and psychosocial dem ands of work are associated with low back pain. Methods. A case-control approach was used. Case subjects (n = 137) reported a new episode of low back pain to their employer, a large automobile manuf acturing complex. Control subjects were randomly-selected from the study ba se as cases accrued (n = 179) or were matched to cases by exact job (n = 65 ). Individual, clinical, and psychosocial variables were assessed by interv iew. Physical demands were assessed with direct workplace measurements of s ubjects at their usual jobs. The analysis used multiple logistic regression adjusted for individual characteristics. Results. Self-reported risk factors included a physically demanding job, a poor workplace social environment, in-consistency between job and education level, better job satisfaction, and better coworker support Low job contro l showed a borderline association. Physical-measure risk factors included p eak lumbar shear force, peak load handled, and cumulative lumbar disc compr ession. Low body mass index and prior low back pain compensation claims wer e the only significant individual characteristics. Conclusions. This study identified specific physical and psychosocial deman ds of work as independent risk factors for low back pain.