Do you feel like one leg is shorter than the other? Don’t worry, I am here to tell you… it probably is. This is referred to as ‘Leg Length Discrepancy’ and it is very common. In fact, it occurs in roughly 90% of the population1.
The Leg Length Discrepancy can range from a fraction of an inch to several inches. The excessive distance is usually what determines the severity of the symptoms (pain!) that you are experiencing.
This article will help you identify the causes, symptoms, and treatment options available. Like most things, I believe you can address this issue and treat it yourself with just a little bit of guidance.
Let’s get started…
|Table of Contents|
|Two Types Of Leg Length Discrepancy|
|How To Tell If You Have It|
|Treatment For Your Unequal Leg Length|
Two Types of Leg Length Discrepancy
1.) Structural Leg Length Discrepancy
Differences in leg length are categorized as structural when there is an actual difference in the length of the femur or tibia in one leg versus the other. This is usually present from birth but there can be other causes (see ‘What can cause a structural difference?’ below).
2.) Functional Leg Length Discrepancy
In Functional Leg Length Discrepancy, the femur and tibia of both legs are actually the same length from top to bottom. However, one will appear longer (or shorter) due to dysfunction at the:
What Causes Uneven Leg Length?
What can cause a Structural Difference?
Structural differences are usually discovered early on in life and usually due to a congenital anomaly that will alter the alignment of the hip, such as coxa vera or even a dislocated hip. Other causes can include:
- Broken bones –
- A broken bone can slow down its growth, especially if there is any shattering or separation of the pieces.
- If there is a fracture, the risk is that the bone will heal and grow more rapidly then the rest of the bone, also leading to a difference in size.
- Bone Tumors – The tumor itself as well as the required treatment can affect the rate of growth in a child’s bone. Unfortunately, uneven leg length ends up being the the least of the family’s worries.
- Osteomyelitis – This infection of the bone marrow usually ends up damaging the growth plates (which ultimately leads to different rates of growth).
Growth Plate Injuries
- These areas of rubbery cartilage at the ends of long bones are where new bone growth occurs in adolescents. Whether through physical injury or pathology, damaged growth plates will alter the rate of bone growth in children.
- In children this is called ‘juvenile arthritis’. It is present in an estimated 300,000 children in the United States2. Like adult arthritis, it causes inflammation of the joints and their constituents. Unlike adult arthritis, juvenile arthritis can cause leg length discrepancies by affecting the rate of bone growth.
What can cause a Functional Difference?
Although not exclusive to adults, we are more likely to experience functional leg length differences because we have had more time to alter (‘mess up’) our bodies. From the top down:
- Scoliosis, slipped discs, or even bad posture can affect the alignment of you pelvis and hips and present as uneven leg length.
- Prolonged sitting combined with tight hip flexors and rigid lumbar spine can lead to abnormal innominate rotation (rotation of one side of the pelvis about the other). This changes the elevation at which the femur will sit in the socket.
- At the knee, genu valgus or varus change the angle at which the upper and lower leg bones articulate and present as an obvious functional difference in leg length.
- Malalignment of the ankle or even a fallen arch on one foot will cause you to stand differently and perceive a difference in the length of your legs.
- The other significant possibility is the presence of arthritis. A decrease in joint space at any of the above-mentioned joints will functionally change the length of your leg in stance.
The most obvious symptom of Leg Length Discrepancy is having one leg longer than the other. These different lengths can be easy to ignore. As stated at the top, 90% of the population experiences this phenomenon and go about their days quite normally.
If the limb length discrepancy is mild, the symptoms may also be mild and many of us will not be motivated enough to seek help/treatment. However, in 2017 Eliks, et al. found that a 2cm difference was enough to affect postural control and lead to a cascade of symptoms3.
Common symptoms can include:
- Low back pain
- Hip pain
- Knee pain
- Ankle pain
- Associated abnormal alignment in all above-mentioned joints
- Fatigue and chronic pain
- Poor posture (which sets off a vicious circle of related symptoms)
- Tilted Shoulders
- Hyperextended knee on the short leg
- Flexed stance phase on the long leg
How To Self-Diagnose A Leg Length Difference
Self Test #1: Observation
- Lay face up on the floor with no shoes, relax.
- Ask friend or family member to place one hand on each of your hips and gently rock them back and forth for 45-60 seconds to loosen any tight muscles.
- Once completely relaxed, have friend observe your two ankle bones and note which is longer.
Self Test #2: Tape Measure
- Lay face up on floor.
- Have friend identify your ASIS (Anterior Superior Iliac Spine) and your Medial Malleolus.
- Using a cloth tape measure, measure the distance from the ASIS to the Medial Malleolus.
- Use the average of two measurements and compare to other leg.
- The average of two tape measurements of the distance between the ASIS and medial malleolus appears to have acceptable validity and reliability when used as a screening tool for assessing LLD4.
Self Test #3: Blocks
- Stand in front of a seated observer and have them locate your ASIS as above.
- Add blocks under your foot of the leg that has the lower ASIS until the two landmarks are at equal height in the observer’s eyes.
- Step off of the blocks and measure the combined height of the blocks for your “indirect measurement.”
- This method is actually ‘slightly more reliable and accurate than using a tape measure5.’
Treatment For Your Unequal Leg Length
What can you do right now?
- Heel Lift – These are most successful if the distance between your shorter leg and longer leg is 1 inch or less. A relatively cheap treatment option, heel lifts can (sometimes) provide immediate relief to back pain, knee pain, and abnormal walking patterns.
- Stretch and Strengthen – If your legs are uneven due to a muscular imbalance at your low back or hips, the appropriate stretches to muscles such as multifidus, obliques, and hip flexors (to name a few) may help to lower the functionally-shortened leg to the level of the unaffected leg. Similarly, a fallen arch on one leg and not the other can be relieved with plantar fascia exercises for an ‘easy’ fix.
Do you need Physical Therapy for your LLD?
A Physical Therapist can provide a more in-depth evaluation and can be especially helpful if you are having trouble figuring out what is causing the leg length difference. As stated above there are innate structural causes and there are functional causes.
Sometimes the solution is easy and involves addressing just one piece of the puzzle (low back, hip, knee, ankle, or foot). More often, and especially in adults, there are multiple pieces of the puzzle that should be addressed to form the whole picture. This is where a professional physical therapy evaluation and consultation can be helpful to get you on the right track.
Yes, if you need a prosthetic.
Additionally, a physical therapist can help to arrange collaboration with a podiatrist and/or a prosthetic who can create you a custom shoe insert or prosthetic device.
Prosthetics can work very well for you if you have a very large leg length discrepancy but are not a candidate for surgery. An appropriate and custom-made prosthetic can ‘improve the gait as well as the appearance, could be fitted to the patient without the prior need of operative correction and could be well disguised under any loose fitting garment.9‘
Surgery may be considered if the difference in your leg lengths is greater than 4 to 6 centimeters. Ultimately it will involve a comprehensive discussion between your orthopedic surgeon and yourself.
- Leg Shortening Procedures:
- Bone Resection: This is an option for adults or adolescents who are done growing. Your surgeon will remove a section of bone to equalize the length.
- Epiphyseal Stapling: In the growing child, the surgeon will staple the growth plates on the longer leg, slowing its growth. When the shorter leg catches up, the staples are removed to allow both to continue to grow.
- Epiphysiodesis: The surgeon will position a block of bone over the growth plate to stop further development. The other leg continues to grow. There is a much higher risk of ‘over-shooting’ or ‘under-shooting’ with a 7% rate of complications6.
- This is a popular and proven option if there is an angular deformity7.
- Leg Lengthening Procedures:
- External Fixation: Your surgeon will cut the shorter bone into two pieces and attach an external fixator. The fixator will be manipulated every few days over the next several months to mechanically separate the two pieces of bone. The very minor separation will stimulate new bone growth. When the length is even, the bones are given a period of time to harden and the fixator is removed.
- Internal Fixation: A magnetically telescoping nail is inserted in the bone and serves the same function as an External Fixator. The nail will telescope (lengthen) an average 0.5 +/- 0.1 millimeters each day8. This procedure also spans several months and includes non-weight-bearing status.
A Word From Rehab Revolution
Unequal leg length is very common and easy to ignore. You might think you are imagining the difference in leg length. Or you might figure that there is nothing you can do about it. This is a mistake that I want to help you correct.
Whether anatomical or structural, uneven leg length is a major cause for ankle, knee, hip, and back pains. It will affect how you walk, how you stand, and if left untreated… cause you great pain as you grow older.
In most cases, conservative treatment is well tolerated and successful. You just have to know where to start and also be able to look at the body as a whole, not just one piece at a time.
If you still have questions or need guidance, feel free to just ask.
Dan Kristoff PT, DPT is recognized as one of the Top Physical Therapists in Ohio. In his 10+ yrs as a physical therapist, he has helped thousands of patients recover from illness and debility. His company, Rehab Revolution, is less than a year old and has already helped hundreds of clients take back control of their health.
- Murray KJ, Azari MF. Leg length discrepancy and osteoarthritis in the knee, hip and lumbar spine. J Can Chiropr Assoc. 2015;59(3):226-237.
- Prakken, B., Albani, S., and Martini, A. Juvenile idiopathic arthritis. Lancet. 2011;377:2138-49.
- Eliks M, Ostiak-Tomaszewska W, Lisiński P, Koczewski P. Does structural leg-length discrepancy affect postural control? Preliminary study. BMC Musculoskelet Disord. 2017;18(1):346. Published 2017 Aug 9. doi:10.1186/s12891-017-1707-x
- Gurney B. Leg length discrepancy. Gait Posture. 2002;15:195–206.
- Sabharwal S, Kumar A. Methods for assessing leg length discrepancy. Clin Orthop Relat Res. 2008;466(12):2910-2922. doi:10.1007/s11999-008-0524-9
- Makarov MR, Dunn SH, Singer DE, et al. Complications Associated With Epiphysiodesis for Management of Leg Length Discrepancy. J Pediatr Orthop. 2018;38(7):370-374. doi:10.1097/BPO.0000000000000835
- Wiemann JM 4th, Tryon C, Szalay EA. Physeal stapling versus 8-plate hemiepiphysiodesis for guided correction of angular deformity about the knee. J Pediatr Orthop. 2009;29(5):481-485. doi:10.1097/BPO.0b013e3181aa24a8
- Wiebking U, Liodakis E, Kenawey M, Krettek C. Limb Lengthening Using the PRECICETM Nail System: Complications and Results. Arch Trauma Res. 2016;5(4):e36273. Published 2016 Aug 23. doi:10.5812/atr.36273
- Devnani AS. The orthotic management of the congenitally short lower limb–a new appliance. Singapore Med J. 2000 Nov;41(11):534-7. PMID: 11284611.
- Cepela DJ, Tartaglione JP, Dooley TP, Patel PN. Classifications In Brief: Salter-Harris Classification of Pediatric Physeal Fractures. Clin Orthop Relat Res. 2016;474(11):2531-2537. doi:10.1007/s11999-016-4891-3.