Leg length difference (LLD) is primarily when the hips are not level, causing a limp from side to side. Most practitioners divide LLD into anatomical or functional. Anatomical is when there is a true difference in the length of the tibia/fibula or the femur bone, or both. While functional LLD are either the shortening or lengthening of a limb, secondary to joint contracture or muscle imbalances.
Symptom of Leg Length Discrepancy
LLD do not have any pain or discomfort directly associated with the difference of one leg over the other leg. However, LLD will place stress on joints throughout the skeletal structure of the body and create discomfort as a byproduct of the LLD. Just as it is normal for your feet to vary slightly in size, a mild difference in leg length is normal, too. A more pronounced LLD, however, can create abnormalities when walking or running and adversely affect healthy balance and posture. Symptoms include a slight limp. Walking can even become stressful, requiring more effort and energy. Sometimes knee pain, hip pain and lower back pain develop. Foot mechanics are also affected causing a variety of complications in the foot, not the least, over pronating, metatarsalgia, bunions, hammer toes, instep pain, posterior tibial tendonitis, and many more.
Cause of Leg Length Discrepancy
From an anatomical stand point, the LLD could have been from hereditary, broken bones, diseases and joint replacements. Functional LLD can be from over pronating, knee deformities, tight calves and hamstrings, weak IT band, curvature in the spine and many other such muscular/skeletal issues.
Treatment of Leg Length Discrepancy
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.