Leg length difference - when does it matter?

Leg length difference

Many people have a leg length difference. If we were to measure everyone, we know that more than 90% of all people have a leg length difference. The average difference is about 0.5 cm. In about 20% of the population there is a leg length difference of more than 1 cm. And 1 in 1000 has a leg length difference of more than 2 cm. The exact difference must be measured by an X-ray photo which looks at the difference in height of both hips. This is a common and relatively expensive investigation. In practice, we often see that measurements are made from recognizable anatomical points in our body from the hip to the foot. This method is far from perfect but gives an indication of a possible leg length difference. But the most important question is: how important is a leg length difference in relation to pain symptoms?

More than 90% of the population has a leg length difference

Possible cause of pain

When a physiotherapist or doctor discovers a leg length discrepancy, it is easy to point to this as the cause of the pain. But can we really say this directly? Several studies have been carried out into the relationship between leg length difference and pain symptoms. A study in which people with a leg length difference and WITH BACKPLAIN were compared to people with a leg length difference WITHOUT BACKPLAIN showed the following. The average leg length difference in the group with pain was 5.1 mm and the average difference in the people without pain complaints was 5.2 mm. This small difference shows that the measured leg length difference does not contribute very much to the pain complaints. The average leg length difference of the people without pain complaints was even somewhat larger.

Another group where a leg length difference is often measured is people with a hip prosthesis or after a hip fracture. Both can result in a leg-length difference. Although there is an average difference of about 3 centimetres after an operation or fracture, we do not see that these people develop more or less back problems. We also see no change in the long term:

  • development of hip osteoarthritis
  • loss of function
  • comfort
  • satisfaction after surgery

So does it really matter? Do we have to go to this much trouble to fix it?


When does it matter?

To answer this question we need to look at 2 different factors:

  1. The actual difference in length
  2. The individual load level

A leg length difference of less than 1 cm is highly unlikely to be a cause of complaints elsewhere in the body. A difference greater than 1 cm seems to be more relevant, certainly in combination with a high physical load. If there is no question of a higher physical load, we see that this makes little difference.

This means that for people with a leg length of more than 1 cm and a low daily physical load such as cycling or an office job, it is unlikely that the leg length difference is the reason for the symptoms.

What can we do about it?

When this is the case, an insole can be useful to reduce complaints. The height of the sole and the type of sole will differ per person. What is even more important than an orthotic is that other factors, such as physical activity, sleep and capacity, are taken into account. These can all contribute to the reduction of symptoms and the promotion of recovery.

A leg length discrepancy is normal up to a certain limit. When you first hear that you have a leg length discrepancy, it can be quite a shock. People often think that this MUST be repaired. So, please understand that in most cases this is not necessary and that a small difference in leg length is not the reason for possible complaints. It is also not the case that you can develop complaints sooner in the future. No back problems, no arthritis, this does not have to be the case. We are not symmetrical by a long shot. The evidence between deviations in position and pain is very minimal or often non-existent. Focus less on the leg length difference and more on what you can influence!

Knutson, G.A. Anatomic and functional leg-length inequality: A review and recommendation for clinical decision-making. Part I, anatomic leg length inequality: prevalence, magnitudes, effects and clinical significance. Chiropr Man Therap. 13,11(2005)

Paravizi et al,Surgical Treatment of Limb-Length Discrepancy Following Total Hip Arthroplasty. J Bone Joint Surg Am.2003 Dec;85(12):2310-7.

Make an appointment

Other blogs in this category

Dealing with groin pain

Groin pain can have a variety of causes. This is because different structures can all cause pain in the groin. Some structures cause localized pain others are the result of radiating pain from another region of the body. Also.

Training with hyperextensions and integrating them into your training program

What is hyperextension and what do you apply it for?When you want to build strength or muscle mass in your glutes and hamstrings, people often go for a romanian deadlift or cable exercise. The hyperextension is often not the first choice. Shame! Because a study from 2021...

Allon Melchers 3 Tips for losing weight

3 Tips for Losing Weight Nutrition is a difficult term to understand. It encompasses many different factors, each of which affects how our bodies react to it. Some people want to lose weight and feel like they've done everything they can without...

Sprained ankle - inversion trauma

Sprained ankle or inversion trauma Almost everyone has gone through their ankle at one time or another. In most cases, the ankle folds inward. This movement of the ankle is called inversion. Hence the name inversion trauma. The symptoms are...

Sleep & work performance

You have probably experienced it. Those days when you doubt whether you'll get through the day after a bad night. Lack of sleep seriously affects the quality, effectiveness and creativity of your work. And when you are in charge it can...

Promote muscle recovery with your diet

By: Romy and Lieke - Fit female academy Within 30 minutes drinking a protein shake for optimal muscle recovery and maximum protein eating? We think this really fits under the heading of "Bro science". We'd be happy to explain what you can do to strengthen your muscles and...

Behind the neck press, right or wrong?

The shoulder press behind the neck press is an exercise that has been used in the gym since the early years of bodybuilding. In recent years, however, a trend has emerged around this exercise in which it is claimed that it can...

Load vs. Tolerance

In our previous blog we explained that anatomical variation such as a leg length difference, the position of your pelvis or the curvature of your back in most cases is not as important as most people (and therapists) think. Consider that more than 85% of...

Vertebrae out of alignment? Leg length differences? A back that is too hollow or too convex?

Within physiotherapy we often see that the cause of lower back pain is often explained by wear and tear and aging on the one hand and on the other hand by our posture or the position of the spine. Leg length difference? One of the best known examples is a leg length...

Heel spur - plantar fasciitis

A heel spur is an inflammation of the tendon plate of the foot that often occurs in men and women between the ages of 40 and 60. We often see that someone with heel spur complaints has started to do more sport (think of running) or has started to wear other shoes. Because of the pain, it can...
Sign up for our newsletter

Sign up for our newsletter

Receive our latest blogs every month!

Thank you for your subscription. You will now receive our monthly newsletter.