Leg Length Discrepancy

by Brent Hearn • 

Perhaps you’ve suspected—or been told—at some point by someone (a physician, chiropractor, coach, for instance) that you or your child have “one leg shorter than the other.” Or maybe you’ve noticed a limp or “hitch” in your or your child’s gait and wondered if it might be caused by a difference in leg length. Whatever the case, it’s completely understandable that you’d have some questions.

The purpose of this article is to address a few of those questions. Hopefully you’ll come away armed with a bit more knowledge and enough context to know whether your or your child’s leg length discrepancy is cause for concern—and if so, what your next steps should be.

What the heck is LLD?

LLD can refer to either “limb length discrepancy” or “leg length discrepancy.” (This article is only concerned with the latter, so assume in all cases the first “L” stands for “leg” for our purposes.)

What are the types and causes of LLD?

LLD can be classified into “structural LLD” (also called “true LLD”) and “functional LLD.” With true LLD, there’s an actual structural difference in leg length. This could be congenital (present from birth) or can arise due to a variety of other reasons, including (but not limited to) a broken bone, surgical repair, a tumor, or radiation exposure.

With functional LLD, there only appears to be a discrepancy in length due to some other condition—a muscular imbalance, low joint mobility, a tilt in the pelvis, etc. (Don’t misunderstand; just because functional LLD doesn’t involve an anatomical discrepancy doesn’t mean it can’t cause problems.)

Is my (or my child’s) LLD a cause for concern?

In most cases, no. A slight difference in leg length is common; in fact, most people in the world have some degree of LLD. Differences less than two centimeters are negligible and might not be noticeable, even to the person affected.

However, in other cases, yes. Larger discrepancies can affect a person’s gait, mobility, and posture. If the discrepancy is left untreated, the person affected may suffer from some combination of the following symptoms (depending on severity):

• a limp
• hip pain
• knee pain
• ankle pain
• back pain
• degenerative arthritis
• scoliosis

What should my next steps be?

There are many different treatments available for LLD, depending on its cause, severity, and age of the person affected. They can range from less invasive (shoe inserts, chiropractic, physical therapy, etc.) to a variety of surgical interventions.

If you suspect that you or your child may need to be evaluated for LLD, schedule an appointment with your chiropractor, primary care physician or your child’s pediatrician. They’ll be able to refer you to a specialist if necessary.

Sources:

Boston Children’s Hospital: Limb Length Discrepancy

Children’s Hospital of Philadelphia: Limb-length Discrepancy

Columbia University Irving Medical Center – Columbia Orthopedics: Leg Length Discrepancy