Exercise Has No Impact on Knee Osteoarthritis

Affected older people can safely keep active, study confirms.

By Alan Mozes
HealthDay Reporter
Wednesday, January 31, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, Jan. 31 (HealthDay News) -- Even for the overweight, regular moderate exercise does not hasten or delay the onset of osteoarthritis of the knee in older individuals, new research reveals.

The finding undercuts the notion that exercise might have a protective effect against osteoarthritis. However, at the same time, it suggests that those already burdened with an elevated risk, such as overweight seniors, can safely remain active.

"There was fear that weight-bearing exercise among overweight people might put the very people who need it most at risk of getting knee arthritis and knee pain, but this study suggests that is not the case," said study author Dr. David T. Felson, chief of Boston University's Clinical Epidemiology Research Training Unit. "There shouldn't be any concern."

The findings are published in the February issue of Arthritis Care & Research.

According to the National Institutes of Health, osteoarthritis is the most common form of arthritis in the United States, affecting more than 12 percent of the population.

The painful degenerative joint disease is characterized by a breakdown of the shock-absorbing cartilage that shields bones where they contact joints. Osteoarthritis is more prevalent among the elderly, especially women, but it can also develop among younger men and women.

In their study, Felson and his colleagues tracked the exercise habits and incidence of knee osteoarthritis for almost 1,300 men and women in Massachusetts. The study lasted for more than a decade, with participants averaging just over 53 years of age at the trial's outset.

Initial activity surveys were completed in 1991 and 1992 to assess the types and intensity of regular exercise being practiced. In 1993 and 1994, and once again from 2002 to 2005, the researchers took knee X-rays and had participants fill out knee function questionnaires. Just over one-quarter of the participants had already developed some form of knee pain by 1993-1994.

The researchers found that most of the men and women said they walked regularly for exercise.