Leg Length Difference

Also known as a limb length discrepancy, a leg length difference describes a physical difference in the length between a person’s legs when two anatomical points are measured. While it’s not surprising that many people have a small difference given that our bodies are not perfectly symmetrical, significant differences in length have the potential to cause pain and other problems not just at the legs but the hips and back, affecting a person’s daily comfort, movement and their quality of life. 

Having a leg length difference can create a tilt at the hips and various joints in the feet and legs, and may even adversely affect your spine too. It can result in other joints and structures being overloaded, stressed, stretched and restricted in their function. This can present in a variety of symptoms, from a limping gait to shorter steps and walking speed, to overuse injuries, stress fractures - and hip, knee and back pain. As such, the signs of a leg length difference can include everything from:

• Markedly different wear patterns between your shoes
• Hip hitching or a exaggerated bending of the knee when completing your gait analysis
• Recurrent foot pains and problems (i.e. tendinopathies, often in multiple areas)
• Foot or leg fatigue, or joint aches
• Uneven steps - shorter steps on the side with the shorter leg
• Pain in the hips, knees or back
• Stress fractures or other problems that don’t appear to have a traditional cause
  

In order to understand the cause of a leg length difference, we need to understand the two types of length differences you can have: structural and functional. 

A structural leg length difference is measured when a person is not bearing any weight on their feet, such as when they’re laying down. Finding a difference in the structural length reflects directly on there being a difference in the length of the femurs (thigh bones) or tibias (shin bones). This difference may well be a natural difference you were born with, or could be related to a previous injury, disease, or a byproduct of a former surgery like a knee replacement.

A functional difference is measured when a person is standing and bearing weight on their feet - hence when their feet and legs are “functional”. Those with a functional leg length difference may have the same structural leg length when anatomical measurements are taken laying down, but due to the way the muscles, bones, connective tissues and joints work together when standing or walking, a leg length difference is created. We often see functional differences linked to tight, contracted muscles, such as at the hips. We also see it when ligament laxity or tendon dysfunction affects one foot more than the other. Neurological diseases are another common cause for functional differences. A common example is when posterior tibial tendon dysfunction causes one foot to become flatter than the opposite foot. The hip and knee of the flatter foot are more likely to be sitting lower to the ground than that of the other leg, creating a leg length difference.

Simply having a leg length difference, especially a small one, doesn’t necessarily warrant treatment - especially if it is from a natural length variation that you’ve had for decades and hasn’t bothered you. Studies have shown that up to 90% of people will have a 5mm difference, and many will remain asymptomatic. If a leg length difference is paired with pain or other symptoms, however, this does warrant further investigation and treatment. In this case, at home, you may try:

• Wearing newer, supportive footwear that isn’t considerably worn down, as differences in the wear patterns of a shoe (where one shoe wears down faster than the other) can further exacerbate a leg length difference and its symptoms.
• Strengthening and stretching exercises, if you have known tightness and weaknesses and you feel confident in the best approach to address them. Focus on exercises that target the muscles of the hips, quadriceps, hamstrings, and calf muscles to help minimise compensation patterns and improve overall leg function.
• Maintaining a good posture in everyday life can also help to manage a leg length difference. Practice maintaining good posture while sitting, standing, and walking to help minimise any additional strain on the lower back or hips, which may help ease some of your symptoms.
• If you’re in pain, over-the-counter pain medications such as non-steroidal anti-inflammatory drugs (NSAIDs) can be used to manage any discomfort associated with the leg length difference, if it is safe and suitable for you to do so.
• Avoid physical activity that aggravates and worsens your symptoms.

Here at Matt Raden Podiatry, our trusted and experienced podiatrists listen to the concerns, goals and needs of our patients with leg length differences, and utilise a range of evidence-based treatment methods to help you get the best outcome.

Every appointment starts with a comprehensive assessment to measure a suspected leg length difference, determine whether it is structural or functional in nature, and understand the impact that it is having on the biomechanics of your ankles, feet and legs. We’ll then create a tailored treatment plan based on your results that focuses on bringing the legs into greater balance and alignment. To achieve this, we may use:

• Orthotics (insoles) or heel lifts: using custom-prescribed foot orthotics or heel lifts that sit inside your shoe can help raise the shorter leg by bringing it in contact with the ground, while maintaining greater symmetry at the hips and knees. This can go a long way in improving your gait, foot biomechanics, and any painful or uncomfortable symptoms you may be experiencing.
• Footwear assessment and recommendations: wearing unsupportive shoes that have asymmetrical wear patterns can exacerbate both your leg length difference and the effects its having on your body. We will assess the footwear you currently wear on a daily basis (please bring these to your appointment) and can make recommendations as needed, if your current footwear needs updating.
• Stretching and strengthening program: stretching and strengthening exercises can be beneficial in helping address any muscle imbalances that may be contributing to your leg length difference or symptoms..
• Condition-specific treatments - in some cases, the effects of your leg length difference will have led to the development of certain injuries, like tendinopathies, or certain conditions, like corns and calluses. All of this will be considered and addressed in your management plan so you get a holistic and full treatment approach to help you feel and perform your best on your feet.