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