[Epidemiology of musculoskeletal diseases in Japan]

We investigated the prevalence of musculoskeletal disease, such as osteoporosis and osteoarthritis, using Japanese population-based cohort data from the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study. This study, established in 2005, comprised data from 3,040 participants. In men and women, aged ≥40 years, we determine the prevalences of osteoporosis in the L2-4 vertebrae(men, 3.4%; women, 19.2%), femoral neck (men, 12.4%; women, 26.5%), and knee (Kellgren-Lawrence grade ≥2; men, 42.6%; women, 62.4%). The prevalence of lumbar spondylosis, diagnosed as Kellgren-Lawrence grade ≥2, was 81.5% in men and 65.5% in women. In addition, based on data from the Longitudinal Cohorts of Motor System Organ (LOCOMO) study, initiated in 2008 to integrate information from cohorts in eight communities across Japan, we examined the prevalences of knee and lumbar pain. The prevalence of knee pain was 32.7% (men, 27.9%; women, 35.1%) and that of lumbar pain was 37.7% (men, 34.2%; women, 39.4%).