“Sometimes people will complain of low back pain, hip pain, or even groin pain,” Dr. Mehta says. The reason for this is slightly complicated, but having legs that are different lengths can throw off your gait, which causes a cascade of asymmetry in your body, eventually leading to pain.

But Dr. Mehta says he’s also seen patients who say that they just feel “off” when they stand. “There will be subtle things that they try to compensate for but ultimately, as time goes on, they will start to notice hip and low back pain,” he says.

This pain can be constant or it can come and go, like mine, Dr. Anand says. “If you have intermittent back pain, this is worth looking into,” he says. “There is a very simple solution, and it could get better.”

It’s not difficult to diagnose a leg length discrepancy.

This is usually done via X-ray with a calibrated ruler between your legs in a procedure called a scanogram, Dr. Mehta says. “You need to truly measure the legs,” he explains.

Doctors may also do a clinical exam, where they may have you stand with one leg on a wooden block of different heights to see how it feels to you. “It’s similar to when you go to the eye doctor and they ask you which lens is clearer,” Dr. Mehta says. “We’ll ask patients if the block feels too high, too low, or just right. Sometimes they will say, ‘I feel more level with this 1.5 inch block under my foot.’”

There are a few possible solutions for a leg length discrepancy.

Doctors may recommend wearing a lift in your shoe to help correct a smaller leg length discrepancy. “For smaller discrepancies, a lift is all you need,” Dr. Anand says.

But for people with larger discrepancies—considered two centimeters or more—Dr. Mehta says that surgery to lengthen the shorter limb or to shorten the longer limb may be recommended. “You can only put so much of a lift inside the shoe before it becomes unwearable,” he explains. But Dr. Mehta says that surgery is usually considered a last resort. “Even in patients with a larger discrepancy, we will sometimes do a lift to see if it helps first—it’s almost like a test drive,” he says.

Doctors say it’s important to be aware that leg length discrepancies can cause back pain flares.

Dr. Mehta points out that it can be a “challenge” to diagnose leg length discrepancies if you’re having pain, because it’s not what most doctors will initially think of. “But if your imaging is coming up negative for other things, it is a reasonable request to say, ‘Hey, can we look at my leg length?’” he says.

Dr. Anand agrees. “I wouldn’t tell everyone to get this checked out, because back pain can have so many causes,” he says. “But if you’re having many bouts of back pain on and off, it’s worth looking into it. A lot of patients will do really well with a lift.”

As for me, I’m just glad I know what’s behind those back pain flares, and that the solution was relatively simple. So, I will gladly keep wearing a lift in my left shoe for the rest of my life. While I was self-conscious about it at first, I don’t even think about it now. And it’s worth it to be pain-free.

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