The effect of changes in lower limb pain on the rate of progression of locomotor disability in middle and old age: evidence from the NorStOP cohort with 6-year follow-up

Locomotor disability (LMD) is common at older ages, and can lead to other significant disability and mortality. Prevalent pain has been shown to be associated with LMD. This article aimed to assess the association between changes in lower limb pain status (ascertained from a manikin) and changes in the level of self-reported LMD in a sample of UK adults age ≥ 50years, over a 6-year period (data collected at 3-year intervals). There was an average increase in the level of LMD over 6 years. Reports of an onset of lower limb pain were associated with a relative increase in LMD, independently of sociodemographic factors and the onset of selected comorbid diseases. A dose-response relationship was observed between the onset of multiple lower limb joint involvement and more frequent or intense pain and larger increases in LMD. Becoming free from lower limb pain was associated with a relative decrease in LMD, but did not return LMD scores to the level of those who had remained pain-free throughout. This is consistent with a cumulative effect on LMD of recurrent episodes of pain. Lower limb pain may be a key target for prevention and rehabilitation to reduce years lived with disability in later life.