Relationship of a lifelong physical workload with physical function and low back pain in retired women

The effect of heavy work-related physical loads (WRPL) on low back pain (LBP) and impaired physical function has been studied extensively in active workers but not in pensioners.

We compared LBP and physical function in post-menopausal pensioners, divided according to their life-long WRPL into 114 heavy physical workers (HPW), and 391 light physical workers (LPW). LBP and physical function (domains of mobility, home routines) were scored by a questionnaire. Data on age, age at menopause, number of years in retirement, age at menarche, number of pregnancies, body mass index (BMI), femoral neck bone density, WRPL, years spent at work, and smoking were also collected.

HPW were older (p=0.004), had worked fewer years (p=0.001), had reduced mobility (p=0.001), worse LBP (p=0.001) and performed home routine activities worse (p=0.001) than LPW. Logistic regression adjusted for confounders (LBP, home routines and mobility dichotomised at the median) showed that heavy WRPL, aging and high BMI were LBP risk factors, whereas heavy WRPL, high BMI and early menopause were mobility risk factors. The area under receiver-operating characteristic curves showed that predicted probabilities, derived from logistic models, predicted mobility (area 0.816, SE 0.020) better than pain (area 0.643, SE 0.024) (Hanley McNeil test p<0.001).

Lifelong heavy WRPL and high BMI seem to be risk factors for worse LBP and mobility in retired women. Mobility seems to be especially affected by these risk factors, and should be further investigated for prevention purposes.