Ewa Rolston

The Globe's Premier Foot Site

True Leg Length Discrepancy Test


If one scans the literature it readily becomes obvious that leg length discrepancy/asymmetry is a common finding. This fact has been a very controversial topic within chiropractic, and diagnostic rationales have been built around this very common finding.

The object of this column is to consider some of the causes of this discrepancy that the profession may have ignored or not been aware of.Leg Length Discrepancy


Sometimes the cause of LLD is unknown, yet the pattern or combination of conditions is consistent with a certain abnormality. Examples include underdevelopment of the inner or outer side of the leg (hemimelias) or (partial) inhibition of growth of one side of the body of unknown cause (hemihypertrophy). These conditions are present at birth, but the limb length difference may be too small to be detected. As the child grows, the LLD increases and becomes more noticeable. In hemimelia, one of the two bones between the knee and the ankle (tibia or fibula) is abnormally short. There also may be associated foot or knee abnormalities. Hemihypertrophy or hemiatrophy are rare conditions in which there is a difference in length of both the arm and leg on only one side of the body. There may also be a difference between the two sides of the face. Sometimes no cause can be found. This type of limb length is called idiopathic. While there is a cause, it cannot be determined using currect diagnostic methods.


The effects of a short leg depend upon the individual and the extent of discrepancy. The most common manifestation if a lateral deviation of the lumbar spine toward the short side with compensatory curves up the spine that can extend into the neck and even impacts the TMJ. Studies have shown that anterior and posterior curve abnormalities also can result.


The only way to decipher between anatomical and functional leg length inequalities (you can have both) is by a physical measurement and series of biomechanical tests. It is actually a simple process and gets to the true cause of some runner?s chronic foot, knee, hip and back pain. After the muscles are tested and the legs are measured it may be necessary to get a special X-ray that measures both of your thighs (Femurs) and legs (Tibias). The X-ray is read by a medical radiologist who provides a report of the actual difference down to the micrometer leaving zero room for error. Once the difference in leg length is known, the solution becomes clear.

Non Surgical Treatment

The object of treatment for leg length discrepancy is to level the pelvis and equalize the length of the two limbs. Inequalities of 2-2.5 centimeters can be handled with the following. Heel lifts/ adjustable heel lifts can be used inside a shoe where shoes have a full heel counter. Heel lifts may be added to the heel on the outside of the shoe along with an internal heel lift. Full platforms along the forefoot and rearfoot area of a shoe can be added. There are many different adjustable heel lifts available on the market. For treatment of a leg length discrepancy, consult your physician. They may refer you to a Physiotherapist or Chiropractor for determination of the type of LLD. A Certified Pedorthist (Canada) will treat a structural leg length discrepancy with a heel lift or in larger discrepancies a footwear modification.

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Surgical Treatment

Lengthening is usually done by corticotomy and gradual distraction. This technique can result in lengthenings of 25% or more, but typically lengthening of 15%, or about 6 cm, is recommended. The limits of lengthening depend on patient tolerance, bony consolidation, maintenance of range of motion, and stability of the joints above and below the lengthened limb. Numerous fixation devices are available, such as the ring fixator with fine wires, monolateral fixator with half pins, or a hybrid frame. The choice of fixation device depends on the desired goal. A monolateral device is easier to apply and better tolerated by the patient. The disadvantages of monolateral fixation devices include the limitation of the degree of angular correction that can concurrently be obtained; the cantilever effect on the pins, which may result in angular deformity, especially when lengthening the femur in large patients; and the difficulty in making adjustments without placing new pins. Monolateral fixators appear to have a similar success rate as circular fixators, especially with more modest lengthenings (20%).