People with leg length discrepancy, when one leg is longer than the other, usually have a waddling-type gait where the hips seem to move up and down during walking as the body tries to compensate for the inequality. There are two types of leg length discrepancy. The first type of leg length discrepancy involves a structural defect, where one bone is longer or shorter than the corresponding bone of the other limb. This can occur within the femur (upper leg bone) or the tibia and fibular (lower leg bones). Functional leg length discrepancy results from altered mechanics due to a malalignment in the spine or lower extremity.
Common causes include bone infection, bone diseases, previous injuries, or broken bones. Other causes may include birth defects, arthritis where there is a loss of articular surface, or neurological conditions.
Many people walk around with LLD?s of up to 2 cm. and not even know it. However, discrepancies above 2 cm. becomes more noticeable, and a slight limp is present. But even up to 3 cm. a small lift compensates very well, and many patients are quite happy with this arrangement. Beyond 3 cm. however, the limp is quite pronounced, and medical care is often sought at that point. Walking with a short leg gait is not only unsightly, but increases energy expenditure during ambulation. It could also put more stress on the long leg, and causes functional scoliosis. Where the discrepancy is more severe, walking becomes grotesque or virtually impossible.
A qualified musculoskeletal expert will first take a medical history and conduct a physical exam. Other tests may include X-rays, MRI, or CT scan to diagnose the root cause.
Non Surgical Treatment
The way in which we would treat a LLD would depend on whether we have an anatomical or functional difference. To determine which one is causing the LLD you will need to get your legs measured. This is the easiest way to determine if it is anatomical or functional. With a functional LLD we must first determine the cause and treat the cause. Should the cause be one that is not correctable then we may need to treat the LLD as if it were an anatomical or may have to treat the opposite leg to improve one's gait. As for the anatomical LLD, we may start off with a heel lift only in the shoe and follow up to see if we will need to put the lift full sole on the bottom of the shoe. This is determined by the affects that a heel lift in one shoe may have on that knee. Should the LLD be more than 1/4 inch we usually recommend starting between 1/8 inch to 1/4 inch less than the actual amount and let the body adjust to the change and then raise up to the measured amount later.
what happens if one leg is shorter than the other?
Many people undergo surgery for various reasons - arthritis, knee replacement, hip replacement, even back surgery. However, the underlying cause of leg length inequality still remains. So after expensive and painful surgery, follow by time-consuming and painful rehab, the true culprit still remains. Resuming normal activities only continues to place undue stress on the already overloaded side. Sadly so, years down the road more surgeries are recommended for other joints that now endure the excessive forces.