Exercise may be key in healthy joints
For years, doctors assumed that exposing joints to high impact loads could accelerate the development of osteoarthritis.
But experts now know that’s not the case. A review of the evidence to date, published in January in the Journal of Anatomy, concluded that exercise, even high-impact sports such as running, don’t cause arthritis. (Researchers excluded the effect of sporting injuries, such as torn knee ligaments, which are an undisputed cause of arthritis).
Far from causing arthritis, jogging, weight-lifting and other kinds of exercise may help keep joints healthy. Dozens of clinical trials have shown that exercise can reduce joint pain and stiffness, and stabilize joints by strengthening the surrounding muscles.
It’s generally accepted that stronger muscles protect cartilage by absorbing some of the force on joints and by keeping bones in strong alignment. And exercise prevents obesity, a big risk factor for arthritis.
But some researchers now believe that exercise also may stimulate cartilage growth and repair.
Cartilage, like muscles, shrinks if it’s not put to use. In an animal study, immobilizing a limb caused a 20 percent loss of knee cartilage in a matter of weeks.
In a human study reported in August, Australian researchers used MRI’s to compare changes in knee cartilage over two years among 297 older women and men. Those who participated in vigorous physical activity maintained significant cartilage loss, researchers reported in the journal Arthritis and Rheumatology.
In an earlier study, the same Australian group found that sports participation in children is linked to increases in knee cartilage thickness, and the more vigorous the sport, the greater the cartilage growth could provide protection from joint deterioration due to osteoarthritis at an older age.
Joe Rojas-Burke
Oregonian Newspaper, Portland Oregon
joerojas@news.oregonian.com
