I always knew that back pain was something a lot of people struggled with, but I never understood just how debilitating it could be—until I developed it myself.
I was six months postpartum the first time I had a back pain flare. I woke up one morning with the back and butt muscles on the left side of my body painfully stiff. I couldn’t bend over to shave my legs in the shower, and even spitting out my toothpaste was agonizing. Picking up my baby was excruciating and so was sitting down, whether it was while I worked or drove anywhere.
That flare lasted for about two weeks. I’ve been a competitive distance runner for most of my life, and I chalked the pain up to pushing my mileage too soon after having a baby. But about four months later, it happened again. And again. The flares were spaced far enough out that I kept shrugging them off, until I realized I couldn’t anymore. These back pain flares were life-altering when they happened. I had to find a solution.
I saw a slew of back specialists, and none of them seemed to want to try to figure out what was wrong with me. They would glance at my MRI results and either declare that I needed back surgery or that I should get steroid injections to try to calm the flares when they happened. One told me I needed to get stronger core muscles, so I went to work trying to get a six pack. Another declared that I had to give up running forever or I would end up in a permanent flare (I cried). But no one gave me an actual diagnosis or spent enough time to talk me through what was happening in my body.
I went to physical therapy, where I was told a range of possibilities could be behind my back pain, from more minor issues like tight hamstrings to serious health conditions like multiple sclerosis. These potential diagnoses were all just flung around, but none of them panned out when I had more testing done. It took years for me to finally figure out what was wrong with me—and I was shocked that no one had thought of it sooner.
My good friend is a foot and ankle surgeon at a multi-disciplinary orthopedic practice near my home. She had heard all about my frustrating pain issues and recommended I meet with a back specialist at her practice. But after an evaluation, that specialist suggested that I consult with my friend, just to see if she had any new ideas.
She suspected that I might have a limb length discrepancy in my leg—which means one leg is shorter than the other—and asked me to get an X-ray to measure the bones in my leg. It was a quick and painless scan that showed her hunch was right. My left leg was a centimeter shorter than my right leg. As she explained to me in a follow-up visit, this was throwing my entire body out of alignment, prompting my muscles to tighten up, and causing spasms every few months when my body couldn’t take it anymore.
The solution was simple: I would wear a one centimeter cork heel lift inside my left shoe to balance things out. I wasn’t thrilled with the idea of having to do this forever, and I was a little embarrassed at how it would look in open footwear, like sandals. But I ended up buying a ton of cork heel lifts, glueing them into the insole of my left shoes, and getting over myself. I haven’t had a back pain flare since. That was five years ago.
Research suggests that up to 90% of the population has some type of leg length discrepancy under one centimeter. In most cases, that’s due to differences in length in the femur (aka thighbone) and tibia (the shinbone), according to the American Academy of Orthopaedic Surgeons (AAOS).
That mismatch in lengths can cause hip, knee, or back pain. But, like all health conditions, there is a range here. Some people can have smaller differences that cause no symptoms, while others have larger leg length discrepancies that can impact their quality of life.
But despite how common leg length discrepancies are, this never even came up in the repeat visits I had with back specialists and physical therapists. “This is something that can cause back pain, but it’s not something every clinician or practitioner thinks about, especially in someone who is athletic,” Samir Mehta, M.D., an associate professor of orthopaedic surgery and chief of Orthopaedic Trauma Service at Penn Medicine, tells SELF.
Dr. Mehta says he usually diagnoses patients with leg length discrepancies when they’re referred to him by a physical therapist. “They know that something doesn’t seem right—maybe someone is walking with a weird gait or they feel off,” he says. “But most people aren’t thinking of a leg length discrepancy off the bat when a patient has back or hip pain.” Because of this, a leg length discrepancy may be picked up by accident while looking for something else, Neel Anand, M.D., orthopedic spine surgeon and director of the Cedars-Sinai Spine Center in Los Angeles, tells SELF.
Making things more complicated is that you can have what’s known as an apparent leg length discrepancy, where it looks like your leg lengths are off due to tight muscles or scoliosis (where your spine develops a sideways curve), versus an actual leg length discrepancy, where the length of your bones is different, Dr. Mehta says.
Back pain can also have a huge range of causes, making it hard to narrow the field, Dr. Mehta says. “There are a lot of other things higher on the list that can cause back pain—muscle strains, herniated discs, osteoarthritis…,” he says. “But if the cause is a leg length discrepancy, this is typically something that will take a year or sometimes longer before it’s picked up.”
Dr. Mehta has worked with patients with a range of leg length discrepancies, and everyone’s experience is slightly different. Some people are born with this, which is likely what happened in my case, or it develops as you grow. Others may develop a leg length discrepancy after a fracture, infection, or bone disease.
“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.”
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.’”
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.
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.
