Sometimes, a straightforward fix can help alleviate lower back, hip, or knee pain caused by osteoarthritis (OA). One often-overlooked cause is leg-length inequality (LLI), where one leg is slightly shorter than the other.
A 2018 study published in Arthritis Care & Research found that LLI is a modifiable risk factor for OA in the knee, hip, or lower back. Even a small difference in leg length can increase stress on joints, contributing to pain and OA development. The study noted that individuals with LLI were approximately 1.5 times more likely to develop OA symptoms within a few years.
You may not notice a slight leg-length difference, but it can still affect your body. The shorter leg experiences higher impact with each step, as it travels farther to reach the ground, increasing stress on the knee and hip. This can also strain hip muscles, leading to discomfort on the shorter-leg side. Researchers estimate that up to 70 percent of people have some degree of LLI, with differences as small as 0.5 cm linked to OA risk, according to studies from institutions like Duke University.
LLI can also stem from spinal conditions. For example, scoliosis, where the spine curves sideways, or osteoporosis, which can compress the spine, may cause one leg to appear shorter, mimicking LLI's effects.
The most accurate way to diagnose LLI is through radiographic imaging, measuring from the top of the thighbone to the ankle. However, experienced physical therapists or podiatrists can assess leg length and recommend custom shoe inserts or heel lifts to correct the imbalance. If you want to try addressing the issue yourself, a drugstore heel lift (slightly thicker, around 0.5'1 cm) may help reduce pain. Test it for a few weeks to see if symptoms improve, but consult a healthcare provider for persistent pain or to confirm LLI.
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