Cumulative low back load at work as a risk factor of low back pain: a prospective cohort study.
OBJECTIVE
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.
MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands.
Pieter
P
Coenen
Idsart
I
Kingma
Cécile R L
CR
Boot
Jos W R
JW
Twisk
Paulien M
PM
Bongers
Jaap H
JH
van Dieën
D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D012090:Cumulative Trauma Disorders / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D017770:Lifting / Q000009:adverse effects; D016015:Logistic Models; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D011187:Posture; D011446:Prospective Studies; D012307:Risk Factors; D013131:Spine / Q000503:physiopathology; D014741:Video Recording; D016474:Weight-Bearing / Q000502:physiology*