Cumulative Low Back Load at Work as a Risk Factor of Low Back Pain: A Prospective Cohort Study

Pieter Coenen,Cécile R L Boot,Jos W R Twisk,Idsart Kingma,Jaap H Van Dieën,Paulien M Bongers

doi:10.1007/s10926-012-9375-z

Abstract

Purpose Much research has been performed on physical exposures during work (e.g. lifting, trunk flexion or body vibrations) as risk factors for low back pain (LBP), however results are inconsistent. Information on the effect of doses (e.g. spinal force or low back moments) on LBP may be more reliable but is lacking yet. The aim of the present study was to investigate the prospective relationship of cumulative low back loads (CLBL) with LBP and to compare the association of this mechanical load measure to exposure measures used previously. Methods The current study was part of the Study on Musculoskeletal disorders, Absenteeism and Health (SMASH) study in which 1,745 workers completed questionnaires. Physical load at the workplace was assessed by video-observations and force measurements. These measures were used to calculate CLBL. Furthermore, a 3-year follow-up was conducted to assess the occurrence of LBP. Logistic regressions were performed to assess associations of CLBL and physical risk factors established earlier (i.e. lifting and working in a flexed posture) with LBP. Furthermore, CLBL and the risk factors combined were assessed as predictors in logistic regression analyses to assess the association with LBP. Results Results showed that CLBL is a significant risk factor for LBP (OR: 2.06 (1.32–3.20)). Furthermore, CLBL had a more consistent association with LBP than two of the three risk factors reported earlier. Conclusions From these results it can be concluded that CLBL is a risk factor for the occurrence of LBP, having a more consistent association with LBP compared to most risk factors reported earlier.

Highlights

In the past decades, epidemiological studies have contributed to our understanding of the aetiology of low back pain (LBP)
Results showed that cumulative low back loads (CLBL) is a significant risk factor for LBP (OR: 2.06 (1.32–3.20))
CLBL had a more consistent association with LBP than two of the three risk factors reported earlier. From these results it can be concluded that CLBL is a risk factor for the occurrence of LBP, having a more consistent association with LBP compared to most risk factors reported earlier

Summary

Introduction

Epidemiological studies have contributed to our understanding of the aetiology of low back pain (LBP). Risk factors for the occurrence of LBP, can roughly be divided into: personal factors (e.g. age, smoking habits, physical capacity and body weight [1,2,3,4]), psychosocial factors (e.g. stress, social support and job satisfaction [5,6,7,8]), and physical factors [9,10,11,12] Of these physical factors, twisting, bending, lifting and whole body vibrations are the most frequently reported ones associated with LBP [13,14,15]. We hypothesized that CLBL, quantified in terms of low back moments, is associated with LBP and that the association of this dose measure with LBP is more consistent than that of exposure measures that were previously established as risk factors for LBP

Objectives

Results

Discussion

Conclusion