Fig. 1

Flow diagram reflecting how 1127 participants were selected from the original participants. BMI, body mass index; OAI, Osteoarthritis Initiative; PASE, the Physical Activity in the Elderly Scale; ROA, radiographic osteoarthritis; SF-12, The 12-Item Short-Form Health Outcome Survey; SOA, symptomatic osteoarthritis; WOMAC, the Western Ontario and McMaster Universities Arthritis Index.