Why are women more likely to suffer from osteoarthritis?

The problem may be muscles.


“Women are more likely than men to suffer from osteoarthritis, particularly in the knee,” says Mary O’Connor, director of the Musculoskeletal Center at the Yale School of Medicine and Yale New Haven Hospital.

Why the knee? Researchers aren’t sure. But they do know that women with knee arthritis have weaker muscles than men with knee arthritis, and that muscles help protect joints.

“Men have testosterone, which builds stronger muscles,” says O’Connor. And it’s the quadriceps, the group of muscles at the front of the thigh that helps the knee absorb the impact of walking and other activities.

Arthritis is also more debilitating in women.

“If you take a group of men who are going to have a knee replacement and you compare them with men of the same age with healthy knees, the guys who are going to have surgery have weaker quad muscles in that leg,” O’Connor explains.

“But when you do the same comparison in women, the difference in quad strength and walking speed between those having knee replacement and those with healthy knees shows that women with knee arthritis have much greater muscle weakness and walking limitations compared to men.

“The way I explain it to my female patients is that arthritis affects you more severely, particularly with more associated muscle weakness.”

Lighten the load.

Whether you have arthritis or not, the best thing you can do for your knees, says O’Connor, is to keep from gaining weight.

“Just  10 pounds of extra weight increases the load on the knee by 30 to 60 pounds,” she notes. “That may explain why overweight women are four times more likely to develop arthritic knees than women who are a healthy weight.”

Arthritis and extra weight create a vicious cycle, says O’Connor.

“When people get knee pain from arthritis, they move less. That causes them to put on weight, which puts more pressure on their knee joints and makes their arthritis worse, which makes them move less.” And that makes their arthritis pain even worse.

Exercise as therapy.

O’Connor calls exercise “a form of therapy” for arthritis. “If you keep the knee moving, it helps the flow of synovial fluid, which lubricates the joint.” You also need to do resistance exercises to keep your quads strong. And the younger you start, the better.

“Women should look at the longer-​term picture. If we want to live well into our 80s or 90s, we have to pay attention to these things in our 40s, 50s, and 60s.”

When you’re sitting in a chair…

Here’s an exercise to strengthen the quadriceps that rheumatologist Emily Farrar, formerly with the Medical University of South Carolina in Charleston, gives her patients.

“When you’re sitting in your chair watching the news at night, take your right leg, slowly lift it out straight in front of you at a 90-degree angle to your body. Then slowly raise your leg up a little higher for a few seconds. You’ll feel that burn in the quadriceps.”

Return your leg to the straight-out-in-front-of-you position. Do 10 of those per leg every day for the first week.

“The next week, do 10 with each leg in the morning and 10 with each leg at night,” says Farrar. “The next week, do 10 with each leg three times a day—in the morning, after lunch or at your desk, and later whenever you have a moment.”

If you increase the strength of the muscles around the joints, “you can decrease the pain in those joints, the knees in particular,” Farrar explains.

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