*Article by Christophe Champs, founder of PODO Clinic and Workshop
You may well have heard in conversation about someone who has found they have one leg longer than the other, perhaps even friends you are out hiking with. This has a name; ‘limb length discrepancy’.
A limb length discrepancy, or LLD, can actually affect both arms and legs but, since at PODO we specialise in all types of locomotion, including the gait, let’s look specifically at leg length discrepancy.
You have a good chance of having the condition yourself – more than 50% of people have a small difference in the lengths of their legs.
For hikers with an LLD, it is easy to picture how such a small misalignment or unbalance between the legs can damage our bodies. The problem is the repetition of the same movement happening incorrectly, because of the asymmetry, and the subsequent need of our body to compensate… over and over again. This means that, quite often, one side of our body will deteriorate unevenly.
In my experience, long distance walkers and hikers suffer with “micro traumatism”, which can be more harmful than some proper traumatism.
With hikers specifically, it should also be noted that, on long journeys or expeditions, the footwear has no rest – the cushion is permanently squeezed and never re-plumped, meaning walking shoes get out of shape and this can actually increase the imbalance between both feet and legs.
There are various myths surrounding LLD, which range from one extreme – you will almost certainly need surgery – to another – no one needs to intervene because the LLD is too small to worry about.
So, I thought I should set the subject straight and share the five things you should know about a leg length discrepancy.
1. A leg length discrepancy is not a medical condition that automatically requires treatment
We all love a diagnosis. That moment when the health professional uses some big machines and technical software to put a name – preferably in Latin – to our problem. But I can reassure you now that an LLD is not a condition that automatically requires medical treatment. Sometimes it’s not even a problem.
What you do need to do if you have LLD is to start understanding why you have it, to notice how it impacts your quality of life, comfort, or performance and, most importantly, to find out how to deal with it.
2. Why do we have one leg shorter than the other?
An LLD can develop at any stage in life. It can be visible at birth (congenital) or acquired later, while growing, or it can happen as an adult. An LLD can be post-traumatic, resulting from surgery or from a severe fracture affecting your thigh bone, tibia, fibula, foot or ankle. It can also be caused by a fracture that has healed badly, an infection, a bone cyst, a bone tumour, and so on.
At PODO, I like to remind my patients that only one rule applies while your feet are on the ground: No one is symmetrical. However, although both feet are different, your body always keeps your eyes level on the horizon. That’s because, in between those feet and eyes, every joint, at every level (ankle, knee, pelvis, shoulder, etc.) will adapt in every body plane in order to ensure your eyes remain level.
When it comes to biomechanics, focusing on your alignment, balance, and posture; both static and dynamic; allows us to measure the risks associated with a leg length discrepancy, in terms of direct damages or risks of developing osteoarthritis in the future.
3. Measuring a leg length discrepancy
A standing X- ray is the most common procedure to measure an LLD. However, this is also where I see the most inconsistency in results. And this is a major motivation for writing this article.
Let’s be clear; X-rays are a phenomenal tool to help us assess our bones and joints. But they remain two-dimensional pictures trying to illustrate a three-dimensional reality.
4. Surgery or conservative treatments?
You will best address postural problems with conservative treatments (non-surgical / non-invasive) or radical treatments (ones that aim to cure the disease rather than merely relieve symptoms). But you will only alter the structural factors by getting an orthopaedic surgeon onboard, to either lengthen the shorter leg or shorten the longer one. This is rarely necessary but sometimes it is, and I cannot recommend enough getting opinions from two different consultants and making sure all conservative solutions have been tried and have been unsuccessful before going down this route.
5. What happens next?
It rarely matters whether you have one leg shorter / longer than the other. Up to a certain level of asymmetry or discomfort, we might not even address it with a heel lift or wedge.
Heel lifts and wedges can be added as a conservative treatment, or a pair of orthotics or insoles within, or on, your shoes can be added straight away.
Finally, do NOT try to address an LLD alone: It is not always the source of your problems, it takes knowledge and skill to properly diagnose it, addressing it is a tricky task and, most importantly, the wrong solution will simply worsen the problem.