Old Bad Beliefs Die Hard: The Story of the Q Angle

Recently I found it curious that my Google search net snared a knee pain article from a physical therapist urging people to correct their “Q angle.”

It was like coming upon one of those stories about Japanese soldiers being discovered in the jungle decades after World War II ended, skulking about in camouflage, believing that they were still actively fighting the United States.

“Q angle” certainly has an air of mystery and mathematically infused importance, just by the very term. It ought to mean something. Something really important.

Anyway, this is one of those terms that you can spend 1,000 words defining and still fail to make clear. Or you can simply borrow an image and voila:



This physical therapist blogger -- whose clients include “numerous pro athletes from the NFL, NBA, MLS, and the WNBA” -- tells us:

When I see a Q angle that is off, I also see an excessive amount of rotational force absorbed by the knee. Furthermore, the meniscus and other internal structures of the knee are compromised more when the Q angle is increased.

Let me cut to the chase here, because the author doesn’t clearly state the “issue”: He’s basically saying a Q angle that is too large is probably the source of your knee problems. Women tend to have larger Q angles, due to natural anatomical differences, such as wider hips.

A few decades ago, the Q angle was the hot go-to theory among structuralists looking for causes for your aching knee. The thing is though, there’s evidence a bad Q angle is not the boogeyman it’s been made out to be.

If you recall my blog post about the study called “Hip Strength and Hip and Knee Pain Kinematics During Stair Descent in Females With and Without Patellofemoral Pain Syndrome,” perhaps you recall this line I quoted from the researchers’ report:

Many studies have not supported the relationship between an increased Q angle and PFPS [patellofemoral pain syndrome].

Paul Ingraham, who I often cite here, delves into the Q angle more deeply and also bashes the idea that it’s some kind of “aha” measurement for discerning and fixing knee pain. He asks the big question: Does the size of the Q angle reliably measure how the quadriceps is pulling on the kneecap?

He cites a study that looks into this question, and ends up concluding, “Clinicians are cautioned against using the Q-angle to infer patellofemoral kinematics.”

So among researchers, the Q angle theory of knee pain has been discredited. But old theories die hard. That’s a good thing to keep in mind if someone starts in about how your knee problems are due to your Q angle. They may be fighting some long-ago war.