title: Longitudinal associations between physical load and chronic low back pain in the general population: the Doetinchem Cohort Study.
abstract: METHODS
  Prospective cohort study.
  
  
  OBJECTIVE
  We explored long-term associations between physical load exposure and chronic low back pain (LBP) using data from an ongoing population-based cohort study.
  
  
  BACKGROUND
  Physical load in work or daily life is often studied in relation to LBP. Most studies are cross-sectional or have a limited follow-up.
  
  
  METHODS
  Between 1993 and 2007, 4738 men and women aged 25 to 64 years were measured maximal 3 times with 5-year intervals. Physical load in daily activities (9 items, e.g., awkward postures, mechanical vibration) was assessed by questionnaire at 2 measurements and chronic LBP 3 times. Physical load exposure at both measurements was described. Multivariable logistic regression analyses were adjusted for sex, age, education, work status, body mass index, physical activity, and smoking.
  
  
  RESULTS
  Despite stable prevalence rates of physical load exposure, about 50% of the participants exposed changed their exposure during a 5-year period. 7.2% of the participants reported awkward postures at 2 measurements, 8.4% at the first measurement only, and 6.8% at the second measurement only. Among all physical load variables, associations with chronic LBP were found only for awkward postures. An increased risk for incident chronic LBP was found in participants exposed twice to awkward postures. In contrast, only single exposure to awkward postures was associated with persistence of chronic LBP.
  
  
  CONCLUSIONS
  Awkward postures were associated with chronic LBP in the general population. Exposure to awkward postures at 2 measurements with 5 years in between did increase the risk for incident chronic LBP, but not for persistence of chronic LBP.
authors: National Institute for Public Health and the Environment, Bilthoven, The Netherlands. sandra.van.oostrom@rivm.nl
authors: Sandra H
authors: SH
authors: van Oostrom
authors: Monique
authors: M
authors: Verschuren
authors: Henrica C W
authors: HC
authors: de Vet
authors: Hendriek C
authors: HC
authors: Boshuizen
authors: H Susan J
authors: HS
authors: Picavet
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D001696:Biomechanical Phenomena; D059350:Chronic Pain / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D010147:Pain Measurement; D011187:Posture; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D014732:Vibration / Q000009:adverse effects; D016474:Weight-Bearing