View article

To evaluate the association between occupations, sports, life‐long daily activities, and knee osteoarthritis.

In this case–control study, we randomly recruited 480 subjects with knee osteoarthritis, who had participated in the first stage of a community‐based study in Tehran, and compared them with 490 controls. A questionnaire was used to record all occupations, sports, and the details of 10 daily activities. The mean ± SD hours/day spent on these activities were calculated and compared using the lightest activity as reference. Generalized estimation equation was used with each knee as the unit of analysis.

The mean ± SD age and percentage of female distribution was 57 ± 12 years, 69.8% women for cases, and 46.8 ± 15 years, 64.1% women for controls. After adjusting for age, sex, and body mass index, 2 activities were risk factors for knee osteoarthritis: prolonged squatting (odds …