In 90% of the population, one limb is shorter than the other. While limb length discrepancy for the majority of this metric equates to less than half an inch, for others it is more severe. Those with leg length discrepancy especially are likely to experience lifestyle disruptions. Fortunately, there are treatments available at Utah Sports and Wellness to minimize the negative effects of the condition.
What Is Leg Length Discrepancy?
A limb length discrepancy (LLD) is a condition in which one arm or leg is shorter than the other arm or leg. This length difference can appear minor, only a fraction of an inch, or range to much more significant disparities, even several inches. The margin of difference determines just how much the discrepancy alters lifestyle. In comparison to differing arm lengths, leg length discrepancies (lower limb length discrepancies) are more likely to have a significant effect on an individual’s daily routine. Effects are usually most severe in children and adolescents.
Limb length discrepancy has a number of causes. Some children are born with it. For others, the condition can be the result of injury or disease or other congenital dysfunctions. Identifying the cause can inform treatment methods. Some functional causes include foot pronation, muscle deactivation or contraction, and lumbar rotation, while more structural origins include uneven pelvis, femur, or lumbar vertebrae.
Sometimes disease or injury can shorten one leg in comparison with the other. Serious fractures, especially those which do not heal properly, can be to blame, as can osteomyelitis and other bone infections. Sometimes a cysts or tumor in the bone is at the root of the problem.
Leg length discrepancy is generally the result of the shortening of one leg, though leg elongation is a rare cause. Elongation may be caused by hemihyperplasia, where over-production of soft tissue or bone causes one side of the body to grow more than the other. This condition often coexists with vascular conditions like Klippel-Trénaunay-Weber Syndrome.
The Dangers of A Shorter Leg
The body does not like being imbalanced. When leg length discrepancy causes such imbalance, the body does what it can to adjust. This can lead to greater problems, including significant changes in spinal posture and deterioration of soft tissue and bone resulting in diminished postural stability. Disparity in the lengths of a growing child’s legs may contribute to the development of scoliosis.
It is important to keep the pelvis level, but patients with leg length discrepancy have both pelvis and sacrum tilted downward on the side of the shorter leg, which can accelerate deterioration of femoral head containment. The asymmetry leads to low back pain and, depending on size differential, limping and gait truncation and asymmetry.
The size difference between the two legs matters. A difference of as little as 3/8” can lead to knee pain in the shorter leg and increase its risk of developing osteoarthritis. Disparities closer to 3/4” or more increase the likelihood of pain and arthritis in both knees. The longer limb is 73% more likely to fracture, and the majority of necessary hip replacements are on the side with the longer leg.
Diagnosing Leg Length Discrepancy
Proper diagnosis is the key to correcting lower limb length discrepancy. There are three primary orthopedic tests to effectively evaluate the problem. X-ray testing may be required to determine the state of the bones. At Utah Sports and Wellness, we conduct one test on every patient that comes to the office to measure the harmony of leg lengths. The patient lays face-down, and one of our chiropractors checks the evenness of pelvic, hip, low back, and leg positioning.
If a difference between the lengths of the left and right legs is found, it is noted, and our team establishes a treatment plan tailored to the patient. This plan will likely include lifestyle changes, muscle work, and chiropractic adjustments that are geared toward correcting the imbalance.
The treatment for leg length discrepancy always depends upon the condition’s underlying cause and severity. Adjustments and muscle work are the most common means employed to retrain muscles and restore balance. Minute differences can also be mitigated with a small lift in one shoe, though this does not correct the problem and does nothing to help when shoes aren’t worn.
It is easier to correct limb length discrepancies when a patient is young. Posturing in children under the age of 15 can be corrected with monitoring (usually every 3-6 months) and making appropriate corrections. While corrective surgery is available for severe cases, pain relief and unifying growth can usually be achieved through chiropractic means.