Unequal leg length
| Unequal leg length | |
|---|---|
| A girl with a congenital, structural difference in leg lengths walking in a clinic. | |
| Specialty | Rheumatology | 
Unequal leg length (also termed leg length inequality, LLI or leg length discrepancy, LLD) is often a disabling condition where the legs are either different lengths (structurally), or appear to be different lengths, because of misalignment (functionally).
Unequal leg length with a very small degree of difference can be common; small inequalities in leg length may affect 40%-50% of the human population. It has been estimated that at least 0.1% of the population have a difference greater than 20 mm (0.79 in). As of June 2024, that is approximately 8.1 million people total in the human population.