Could Your Leg Or Hip Pain Be From A Leg Length Difference?

When our podiatrists are investigating leg and hip pain, a question we may ask when we spot certain signs and symptoms is whether you’ve ever been told that you have a leg length difference or discrepancy. Many people are surprised by this question – if there was a difference in the length of your legs, wouldn’t you know about it?

The answer is not necessarily. There are two different types of leg length differences, they’re more common than you think, and many people won’t have any signs or symptoms until their pain starts or continues without a distinct cause they can pinpoint – and that’s usually when they come to see us.

Today, we’re giving you the low-down on leg length differences, how they occur, and how they are linked to lower limb pain.

Leg Length Discrepancy: A Brief Overview

It only takes a few seconds of looking in the mirror for most of us to see that we aren’t perfectly symmetrical. We naturally have differences, however big or small, in our physical attributes and structure, as well as the way we move.

Studies looking at leg length differences have found that up to 90% of people have differences with an average 5.2mm – just half a centimetre. While this difference may not have an impact for many, studies also show that differences of approximately 20mm are enough to be statistically significant, leading to symptoms and pains in some people. 

We say ‘some people’ because everyone is different, and compensates for their leg length differences differently – some more effectively than others. In our clinic, we’ve seen some people with a difference of as little as 9-12mm in significant discomfort. We’ve also seen differences of around 20mm that go unnoticed and asymptomatic. On the larger end, we’ve measured leg length differences as big as 50-80mm (and probably more), which can often result after surgery in the leg or hip, or from the effects of arthritis which can compress the joint. There is a wide range, with various causes, considerations and symptoms.

There Are Two Types Of Leg Length Differences

They’re defined as structural and functional. Structural means there is a difference in the length of the bones, namely the femur (thigh bone) or the tibia (shin bone). Whether this difference is natural or is a result of an injury, surgery or disease, one leg ends up being notably shorter than the other.

Functional differences mean that even though we may measure the same leg length on a CT scan or when you’re lying down in the clinic, when you stand up, the way your muscles, bones, connective tissues and joints work together create a leg length difference. Often, this is the result of muscle contracture, particularly at the hips, as well as ligament laxity or tendon dysfunction that affects one foot more than the other. A common example is when one foot is flatter compared to the other. The hip and knee of the flatter foot is more likely to be sitting lower to the ground than that of the other leg, creating a leg length difference.

What Having A Leg Length Difference Means (And How It’s Caused)

Having a leg length difference creates a tilt at the hips and various joints in the feet and legs, and can 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.

Causes of leg length differences can vary greatly, and may include:

• Developmental abnormalities
• Bone injuries which heal in a shortened position
• Injury to the growth plate in a bone during childhood
• Bone disease and infection
• Neurological conditions
• Inflammatory conditions affecting the joints
• Abnormal foot biomechanics
• Contractures of joints or connective tissues
• Ligament laxity
• Natural differences present from birth

Back To Hip And Leg Pain – So They Can Be Connected?

They can, yes. But just because you have a leg length difference to some extent, doesn’t mean that it’s definitely the source of your pain. The human body is incredibly complex and there are so many factors to consider! The best way to find the cause of your pain – and thereby start the correct treatment, is to have an assessment with your podiatrist. 

Here at Marlborough Podiatry, we measure for any inequalities in your leg length, understand how and why it has occurred, understand the symptoms displayed by your body – or we find out that despite having a small difference, it’s actually your new gym program that’s done the damage.

Either way, our experienced, qualified podiatrists are here to help. Book your appointment with us by calling 03 972 2927 or book online here.