Osteoarthritis Knee Exercise Bad in Some
Quad Strengthening May Worsen Disease If Knee Alignment Off
Sharma notes that her study only suggests a problem. Only a clinical trial designed to look at the issue can provide a definitive answer. The soon-to-begin, NIH-funded Osteoarthritis Initiative study may answer this question. Another answer may come from work under way at Indiana University. In an editorial accompanying Sharma's article, IU researcher Kenneth D. Brandt, MD, notes that the results of his knee-strengthening study are being readied for publication.
While Brandt isn't talking about the results of the study, his editorial offers a clue. He says it's too soon to recommend that osteoarthritis patients seek the help of a physical therapist.
J. Robin deAndrade, MD, agrees with Brandt. He's professor of orthopaedic surgery at Emory University School of Medicine and emeritus chairman of Emory's department of rehabilitation medicine. DeAndrade notes that Sharma's study didn't look closely at patients' knee pain. Pain means less strength and more disease.
"What this means is that those patients who start off with strong quads have less pain and arthritis and more activity. A person who has a weaker muscle has more pain and arthritis and less activity," deAndrade tells WebMD. "So it stands to reason that those who start off with less arthritis and more activity -- as indicated by the strength they have -- are going to use their joints more, and hence will tend to progress further. Hence a person who starts off with stronger quads is going to be more active, so over 18 months may progress more. People with weaker quads may have more osteoarthritis to start with, but in 18 months they may not be much worse."
Like Sharma, deAndrade recommends physical activity for people with arthritis.
"I do recommend activity in arthritis. It does keep the muscles strong. It does keep your bones strong. It does maintain the cartilage," he says. "But in a perverse way, activity both protects the joint and advances arthritis. To clarify this contradiction, look at it like this. We have a certain amount of use in a joint. If you don't use it, true, the joint might last longer -- but the leg will be weaker and the bones will be weaker. In the end you might be worse off."