Spine (Phila Pa 1976). 2012 Apr 20;37(9):788-96.
Longitudinal associations between physical load and chronic low back pain in the general population: the Doetinchem Cohort Study
van Oostrom SH
de Vet HC
Prospective cohort study
To explore long-term associations between physical load exposure and chronic low back pain (LBP) using data from an ongoing population-based cohort study
Summary of Background Data
1. Physical load in work or daily life is often studied in relation to LBP.
2. Most studies are cross-sectional or have a limited follow-up.
1. Subjects: 4,738 patients (25~64 yr)
2. Follow-up: 1993~2007, maximal 3 time measurements with 5-yr intervals
* Physical load in daily activities (9 item questionnaire)
1) Mechanical vibration
2) Awkward postures
3) Keeping same posture for a long time
4) Repetitive short movements
5) Bending and twisting trunk
6) Keeping a twisted trunk for a long time
7) Arms elevated
8) Working kneeled or squatted
9) Lifting, carrying, pushing, pulling
* Physical load exposure at both measurements (Physical examination)
* LBP measurement based on the Nordic back questionnaire
4. Multivariable logistic regression analyses
* Sex/age/education/work status/BMI/physical activity/smoking
1. Even with Stable prevalence rates of physical load exposure for 5 years,
>>About 50% subjects changed their exposure in 5 year.
2. 7.2% participants reported awkward postures at 2 measurements,
>>8.4% at the first measurement only
>>6.8% at the second measurement only
3. Among all physical load variables,
>>Associations with chronic LBP were found only for awkward postures.
4. Increased risk for incident chronic LBP in participants exposed twice to awkward postures.
5. In contrast, only single exposure to awkward postures was associated with persistence of chronic LBP.
1. Awkward postures were associated with chronic LBP in the general population.
2. 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.
Lack of consistent definition of awkward postures and LBP
"This comes from Spine (c) 2012 Lippincott Williams & Wilkins, Inc."