To walk faster, keep achy knees active

NORTHWESTERN (US) — Pain and stiffness in the knees caused by arthritis can make crossing a busy street daunting, but a new study shows physical activity improves walking speed.

Staying active produces big benefits for people with knee osteoarthritis, even beyond walking speed. It also promotes healthy joint cartilage and reduces pain, depression, and fatigue, says Dorothy Dunlop, the study’s lead author and associate professor of medicine at Northwestern University.

“This is strong evidence that even a small increase in activity is related to better walking function. The bar for improvement isn’t that high. This should motivate people to get moving, even if they have pain or stiffness,” says Dunlop.

The study is published in the journal Arthritis & Rheumatism.

Federal guidelines recommend adults with arthritis should participate in at least 2.5 hours a week of moderate intensity, low-impact activity in sessions lasting 10 minutes or more. Even if people can’t meet these levels, Dunlop says they should be as physically active as possible.

Dunlop and colleagues surveyed 2,500 participants with knee osteoarthritis. Participants filled out self-reported questionnaires about their physical activity at sites in four large U.S. cities.

Researchers divided participants into four physical activity groups, from lowest to highest, using a general activity score. In the lowest physical activity group, less than half, or 49 percent, walked fast enough to cross a street before the light changed. (Traffic lights generally allow a walking speed of four feet per second.) In the next three higher physical activity groups, 63 percent, 71 percent, and 81 percent, respectively, walked fast enough to cross the street.

The study was sponsored by the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

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