Osteoarthritis Knee Exercise Bad in Some
Quad Strengthening May Worsen Disease If Knee Alignment Off
April 14, 2003 -- If you have knee osteoarthritis, exercise is good for you. But one often recommended exercise might make your disease worse, a new study suggests.
The study already is controversial. It goes against what doctors often advise for patients with knee osteoarthritis. They say to build up strength in your quadriceps, the muscle group that makes up the front part of the thigh and extends the knee.
That might do harm to some, says rheumatologist Leena Sharma, MD, assistant professor at Northwestern University Medical School, Chicago. Sharma's research team studied 237 people with knee osteoarthritis for 18 months.
Strong quad muscles were no problem for knees that lined up normally with the rest of the leg. Those who were bowlegged or knock-kneed, however, had worsearthritis if they had strong quads. So did those knees with side-to-side instability, a condition known as knee laxity.
"In osteoarthritis patients with knee malalignment, quadriceps strength at the beginning of the study predicted greater osteoarthritis. Strength seemed to make the situation worse," Sharma tells WebMD. "People with lax knees also had this sort of deleterious effect of strength on risk of disease progression."
Sharma stresses that exercise is very important for people with knee osteoarthritis.
"It's still very important in all osteoarthritis knees for strength to be maintained," Sharma says. "It's just that the approach taken, we believe, should vary according to knee alignment and laxity. We are not saying patients should let their knees get weak. We're only saying that the state of the knee needs to be considered in how strengthening is done."
Sharma continues to tell osteoarthritis patients to get plenty of physical exercise, particularly aerobic exercise. Her cautions apply only to maximizing strength in the knee. For those with knee malalignment or laxity, she offers these suggestions for osteoarthritis knee exercise:
- Visit a physical therapist and learn a more individually tailored exercise program.
- Do exercises that make muscles work better, rather than exercises that just increase strength.
- Improve muscle endurance rather than strength.
- Consider training in ways of walking -- gait training -- to improve the load on the knee.
- Do exercises that improve knee awareness -- knowing where your knee is in space.
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.