Functional Leg Length Discrepancy

What is Leg Length Discrepancy?

Leg length discrepancy means that the legs are unequal in length. Research suggests that leg length discrepancy can be found in at least 70% of the population.

Some cases are anatomical (orĀ structural), meaning that there is a measured difference in the length of the bones of the leg, or a difference in the structures of the hip, knee, or ankle joints.

Other cases are functional, meaning that the impression of one leg being longer than the other is caused by an imbalance in the muscles, tendons, and ligaments of the hip and leg.

Musculoskeletal Disorders Associated with Leg Length Discrepancy

Unequal leg length can put a great deal of uneven stress on the structure of the body. Both anatomical and functional leg length discrepancy are associated with a number of musculoskeletal disorders, including:

  • lower back pain

  • lumbar scoliosis

  • hip pain

  • knee pain

  • arthritis of the hip and knee

  • iliotibial band syndrome

  • patellar tendinitis

  • Achilles tendinitis

  • stress fractures

  • foot pronation or supination

leg length discrepancy

Treatment for Functional Leg Length Discrepancy

The most common treatment for leg length discrepancy is to put a lift in the shoe of the shorter leg. The lift theoretically evens out the length of the legs, relieving the uneven stress being put on the joints, bones, and soft tissues.

However, in cases of functional leg length discrepancy, a lift does not address the cause of the problem. A lift can actually make symptoms worse by allowing the muscular imbalances to become more pronounced.

Most cases of functional leg length discrepancy are caused by muscles that have become chronically, involuntarily contracted. Tight muscles in the waist and lower back can laterally tilt the pelvis (hiking one side up higher than the other). Tight gluteal muscles and hip rotators can also contribute to one leg appearing to be longer than the other.

Chronic, involuntary muscle contraction can result from repetitive activities and postures, injury, emotional stress, and habitual movement patterns due to handedness. When we repeat certain postures or movements over and over, or if we have a protective reaction to an injury, our nervous system learns to keep certain muscles tight, and we lose the ability to voluntarily relax them. This is one of the negative effects of developing muscle memory. While muscle memory allows us to perform daily tasks efficiently and improves athletic performance, it also allows us to sink deeper and deeper into dysfunctional muscular patterns and do damage to the physical structure of our bodies.

The most effective way to treat functional leg length discrepancy is with neuromuscular education. Most cases of functional leg length discrepancy and associated symptoms can be alleviated by simply retraining the nervous system. Clinical Somatics uses a highly effective movement technique called pandiculation that works with the nervous system to release chronic, involuntary muscle contraction and retrain habitual posture and movement patterns.

If you’d like to learn Clinical Somatics exercises at home, a great place to start is the Level One Course.