“There are things that we know of that cause osteoarthritis that can’t be modified like age or being female. But something like obesity or quadriceps strength is modifiable. You can actually do something about this. So the fact that we have something we know is related to risk and we know people can do something about it is exciting,” Dr. Segal adds.  

In addition to the finding that strong quadriceps muscles protect women, this study was one of the first of its kind to look at the effects of quadriceps strength in men.

Researchers discovered that strong thigh muscles didn’t seem to make as much of a difference in men developing osteoarthritis symptoms, though they aren't sure why.

Experts said the study should send a strong message to women.

“The reason why this study is important is because it shows if you try to maintain good muscle strength, your risk of your knee hurting because of osteoarthritis, is less,” says Mary O’Connor, MD, an orthopaedic surgeon at the Mayo Clinic in Jacksonville, FL.

Dr. O’Connor says this research supports her long-standing belief that patients, especially women, not only need to be more active, but need to do weight lifting exercises too.

“They shouldn’t feel intimidated, because they may be older, about learning how to use the equipment and working on building their muscle strength,” she says.

Dr. O’Connor also says, while this study talks about warding off osteoarthritis, those who already have the condition can also benefit from the message about keeping your muscles strong.

“It’s intuitively obvious. One of the problems is that patients get in a downward spiral where they hurt if they move and then they don’t move and then they get weaker and then there’s less support to their knee joint so they spiral down,” she says. 

“In my perfect universe, everyone would have an exercise routine that would include lifting weights two or three times a week," Dr. O'Connor says. "Lifting weights within their own personal ability to do so. Everyone can lift weights. Everyone can do something."