For Knee, Back, or Hip Pain, Consider This Simple Solution

A sore knee. A stiff back. A nagging ache in the hip. For millions of people dealing with osteoarthritis (OA) or joint pain, these issues can make daily life uncomfortable. But in some cases, there may be a surprisingly simple cause—and solution.

Doctors and researchers say that one often-overlooked cause of joint pain is something called leg-length inequality (LLI), where one leg is slightly shorter than the other. You might not notice it just by standing, but over time, even a small difference can add up.

A 2018 study in Arthritis Care & Research found that people with LLI were about 1.5 times more likely to develop symptoms of osteoarthritis in the knee, hip, or lower back. The study confirmed that LLI is a modifiable risk factor—meaning it’s something that can be corrected to possibly reduce pain and joint damage.

So how does a small difference in leg length cause so much trouble?

When one leg is shorter, your body has to compensate with each step. The shorter leg tends to hit the ground harder, causing more impact on the joints in the knee and hip. The hip muscles on that side also have to work harder, leading to muscle strain and discomfort.

You might not feel this difference when standing still, but during walking or exercise, the extra stress can add up. Over time, it may lead to joint wear and tear, inflammation, and pain.

According to researchers at Duke University, up to 70 percent of people have some degree of LLI. Even a difference as small as 0.5 centimeters has been linked to a higher risk of developing osteoarthritis.

LLI can also be caused by other conditions. For example, scoliosis, where the spine curves sideways, or osteoporosis, which causes bones to weaken and shrink, can make one leg appear shorter, creating the same joint problems.

If you’re dealing with unexplained lower-body pain, it may be worth checking whether leg length is a factor.

The most accurate way to measure LLI is through radiographic imaging, where doctors measure from the top of the thighbone to the ankle. But trained physical therapists or podiatrists can also spot signs of LLI and recommend solutions.

One common fix is a heel lift or shoe insert, which can be custom-made or bought over the counter. Even a small lift—about 0.5 to 1 cm—can help reduce joint pressure and ease pain. Many people find relief within a few weeks of using a heel lift.

If you’d like to try this yourself, start with a moderate lift from a pharmacy and wear it in the shoe on your shorter leg. Keep track of any changes in your pain level. But if discomfort continues, or if you’re unsure whether LLI is to blame, it’s always best to talk to your doctor or physical therapist.

Sometimes the smallest fixes—like a tiny lift in your shoe—can make a big difference in your quality of life.