The difference between leg length discrepancy

Recently, after careful evaluation of an area tennis player who would twist his ankle during a game, it was found that he had a leg length shortage. This leg length discrepancy is what created his "twisted ankle " problem.

Limb length discrepancies of the lower extremity often cause disabling problems for athletes. It is also known as the short leg syndrome. This problem may affect as much as 75-80 percent of the population, resulting in pain in the lower back, pelvis or hip. Pain may also radiate down the thigh (sciatica nerve).

If you have severe hip pain, back pain or recurrent injuries on only one side of your body, there is a good possibility that one of your legs is shorter than the other.

There are two types of limb length discrepancies. The first type is the structural, which is a shortening in the length of the thigh bone or lower leg bone. The second type is a functional shortage, which is actually a position change in the bones during running or walking.

The functional leg discrepancy is usually the result of one foot pronation (inward position) more than the other foot. Pronation causes the arch to flatten, resulting in the leg and thigh to rotate inward. The pelvis will then drop downward, causing a functional shortage of the leg.

The majority of symptoms are usually found on the side of the longer limb because it is in contact with the ground longer and thus absorbs a greater amount of pressure and stress. The short limb also develops various symptoms such as shin splints, which are usually a result of the short leg overstraining while running.

A functional limb length discrepancy will respond well to biomechanical orthotic therapy, and a true structural shortage will require a heel lift. If you have a short leg , with no problems or pain, then do not treat the difference.

Dr. Robert F. Weiss is a podiatrist. He was a member of the Medical Advisory Committee of the 1984 and 1988 Olympic Marathon Trials. Dr. Weiss is a veteran of 35 marathons. For more information visit