Dr. Kiper offers Silicone Orthotics for arch support.

Leg Length Discrepancies

By Dr. Dennis Kiper, DPM

There are two different types of leg length discrepancies: congenital and acquired.

Congenital means you are born with it. One leg is anatomically shorter than the other. Through developmental stages of aging, the brain picks up on the gait pattern and recognizes some difference. The body usually adapts by tilting one shoulder over to the "short" side. A difference of under a quarter inch is not grossly abnormal, does not need a lift to compensate and usually does not have a profound effect over a lifetime.

Differences over a quarter inch can take their toll on the spine and should probably be compensated for with a heel lift. In some cases, the shortage can be so extreme that it requires a full lift to both the heel and sole of the shoe.

The acquired shortage is by far the most problematic. In my practice, I see four problems always associated with acquired shortage:

  1. Iliotibial band syndrome (pain on the outside or lateral part of the knee).
  2. Piriformis syndrome (butt pain, not to be confused with sciatica, where the pain runs down the back of the leg).
  3. Hip pain.
  4. Low back pain.

Contrary to popular belief, the acquired shortage is a pronation problem, first and foremost. The reason is that, while you may look identical on both sides of your body, the left and right don't work exactly the same. The same goes for pronation. As you develop, the brain picks up on the patterns of two feet, recognizing the slight variation in gait. The body compensates by rotating one of the hip bones (called the ileum). The ileum can rotate either backward and downward (called PI Ileum for posterior inferior) or forward and upward (AS Ileum for anterior-superior). This pulls the leg higher into the hip socket, causing the leg to function short, changing the alignment of the muscles around the hip and spine. Unfortunately, this causes those muscles to work unequally and inefficiently, and ultimately causes pain.

This pain is most commonly felt with big mileage on the bike or while running. Non-athletes tend to notice it after carrying heavy loads in one hand. The pain can occur at the end of the activity or the next morning, with accompanying stiffness.

In addition, this functioning shortage puts a mild tweak into the sacroiliac joint, further compounding the motion inefficiency. A visit to a chiropractor will help, but only temporarily.

To see if you have a functional shortage, stand in front of a mirror, relax and let your shoulders drop. If necessary, jump up and down from foot to foot to shake yourself out and let your shoulders fall into place. Look at yourself squarely. Is one shoulder lower than the other?

Step far enough back so you can place your thumbs on the bony points in front of your hips. Can you tell if one thumb is lower than the other? Is it on the same side as the lower shoulder? If so, chances are you have an acquired or functional shortage. This commonly happens on the same side as your dominant hand.

Don't be surprised if you have an acquired shortage. Approximately 85% of the world's population exhibits this condition, and two-thirds of them experience pain related to it at some time in their lives.

What can you do about it? Conditioning and stretching. An overthe-counter arch support to help reduce pronation (which in turn helps reduce the stress and strain of inefficient muscles) and preferably a "soft" lift of a quarter inch, which should be changed every six months.

Look at the heels of your shoes. If you've let them wear down too far, this can contribute to pain flare-ups and injuries.

(Reprinted from Fitness Runner magazine, Holiday 1999 issue)

Heel contact wear secondary to leg length discrepancy