Leg Length Discrepancy

Leg length discrepancy (LLD), one leg being longer than the other, is incredibly common. Several causes can lead to LLD, such as an injury during childhood that influenced the growth rate of one leg. Many adults have a leg length discrepancy and don't even know it.

The average leg length difference in adults is about 1.1 cm and many individuals are entirely asymptomatic. This is because the other regions of the lower body compensate for the leg length discrepancy, thus preventing any problem. If, however, you are struggling with injury and believe LLD might be the cause, seeing a physician is the best way to get an accurate diagnosis.

Measuring leg length can be complicated. Often using a tape measure isn't entirely accurate, so getting an X-ray or CT scan is the most effective way to discover your exact leg length discrepancy.

Despite leg length discrepancy being quite common, there has not been a ton of research completed on its effect on distance running. There has, however, been substantial research on LLD in general. One article by Dr. Joseph C. D'Amico, published in Podiatry Today, gives a great background on how LLD can affect other areas of the body as well as when and how to treat cases.

The most common ailment suffered by those with a leg length discrepancy is lower back pain. This is due to the longer leg which puts extra pressure on the lower back. LLD can also create a plethora of other injuries such as IT band syndrome, plantar fasciitis or runner's knee.

Since a leg length discrepancy can cause so many issues, it would seem like anyone with a discrepancy should seek treatment. Researchers disagree on this, though. Some believe that those with a difference between 1-1.5cm need not do anything if they are asymptomatic.

Others believe that anyone with a discrepancy over 6mm should attempt to fix that discrepancy because the LLD could cause a problem down the road. There is no consensus on who should seek treatment for LLD, but it seems like until further research is completed, those who do not have symptoms should not worry about LLD.

For those who are struggling with pain due to a leg length discrepancy, the most common treatment is to put a heel lift in the shoe of your shorter leg. Another solution that can be used either in addition to a heel lift or independently is to strengthen weak muscles and improve range of motion in the lower extremities. Often, muscular imbalances cause by LLD can be fixed through physical therapy, making it so those with low-level LLD need not seek further treatment.

Remember, leg length discrepancies are incredibly common. Many runners worldwide successfully compete despite LLD. If you are struggling with injury caused by a leg length discrepancy, know that you will get over it and be back running before you know it!