Leg length discrepancy FAQs
What does leg length discrepancy mean?
Leg length discrepancy is when one leg is longer than the other. Having a leg length discrepancy is extremely common and sometimes the differences in leg length can range from one millimetre to more than six centimetres.
What causes a leg length discrepancy?
There are two types of leg length discrepancies:
Structural – this refers to the physical structure of the bones in the leg. If the femur (thigh bone) or tibia (shin bone) are physically shorter than the femur or tibia on the other side, this is referred to as a structural leg length discrepancy.
Structural leg length discrepancies generally occur during the growing years and one leg just grows slightly longer than the other.
Functional – this means that both the femur and tibia on each side are the same length so the leg length discrepancy comes from elsewhere in the body.
Functional leg length discrepancies can occur for many reasons including a previously sprained ankle or muscle strain in the leg or back. Postural habits such as favouring one leg to weight bear whilst standing can also affect the length of the legs.
What does it mean if I have a leg length discrepancy?
Most people have some kind of leg length discrepancy and it’s considered relatively normal to have one leg slightly longer than the other. Up to 0.5cm leg length discrepancy is considered within normal limits. If the discrepancy is more than 0.5cm, the body will start to compensate for the length difference. The larger the discrepancy, the more the body will have to compensate its posture and walking patterns.
How does the body compensate for a leg length discrepancy?
The first way the body compensates for a leg length discrepancy is usually the spine and pelvis as they will have to curve to accommodate the leg length difference. When the spine and pelvis curves in this way, this is known as a scoliosis. Again, scoliosis is very common. Most people have a scoliosis. Small curvatures are usually symptomless and many people aren’t aware they even have one. If the leg length discrepancy is severe, a more pronounced curvature may occur which would need to be checked by a specialist.
What can you do for a leg length discrepancy?
Finding the root cause of a leg length discrepancy is key.
If the leg length discrepancy is functional, working on loosening tight muscles or strengthening the legs and core can be all that’s needed to correct the leg length.
If the leg length is structural, other methods may be used. These include:
Orthotics – this is the most common and least invasive treatment. It involves putting inserts or wedges in the shoes and can be used for discrepancies ranging from two to six centimetres. Foot specialists such as chiropodists can advise the most suitable orthotics.
Epiphysiodesis – this is a procedure which works to slow down the growth of the longer leg to allow the short leg time to catch up. The surgery involves creating a bony ridge to reposition a bone block which tethers the growth plate and therefore prevents future bone growth in the leg.
Bone resection – this surgery involves removing a section of the bone to help equal out both sides and make the leg lengths more even. It is usually done in either adults or children who have stopped growing.
If you are concerned about a leg length discrepancy, feel free to come in for an appointment to discuss it. Most of the time, leg length discrepancies are completely normal and will not cause you any harm or affect your body in the future. If there are any questions I haven’t answered, that you would like to know, don’t hesitate to get in touch!