Do You Need a Heel Lift, and How Big Should It Be?
A heel lift is a wedge placed inside your shoe to correct a leg length discrepancy. Whether you need one, and how thick it should be, depends on an accurate standing measurement of both legs under load. Getting the thickness wrong can make symptoms worse, so precise imaging matters before any lift is prescribed.
Key takeaways
- A heel lift compensates for a shorter leg, helping to level the pelvis and reduce strain up the spine.
- Thickness should be based on a measured difference, not guesswork.
- Lifts are usually introduced gradually, not all at once.
- Standing, weight-bearing imaging gives a more reliable measurement than lying-down scans.
- Prescribing the right lift is a clinical decision for your physiotherapist or podiatrist.
What is a heel lift and how does it work?
A heel lift is a firm wedge, usually made of cork, rubber or high-density foam, that sits under your heel inside the shoe. It raises the shorter leg so that the pelvis sits more level when you stand and walk. Some people call it a shoe lift or heel lift insole.
When one leg is genuinely shorter than the other, your body compensates. The pelvis tilts to the short side, and the spine curves to stay balanced. Over time this can cause pain in the lower back, hip or knee, often on the opposite side to the short leg. A correctly sized heel lift takes the strain off that chain of compensation.
It is worth knowing that not every leg length discrepancy needs a lift. Small differences are common and often cause no trouble at all. A lift is usually considered only when the difference is large enough to produce a noticeable lateral pelvic tilt or ongoing symptoms.
What are the signs you might benefit from a heel lift?
You might benefit from a heel lift if you have a confirmed leg length difference and one or more of the following patterns. These are signs, not a diagnosis, so the decision to use a lift should always come from your clinician.
Your belt or waistband sits noticeably higher on one side.
Persistent ache in the lower back, often on the longer-leg side, that does not settle with standard treatment.
Recurring discomfort in a hip or knee that your clinician suspects is linked to uneven loading.
One shoe wears down faster than the other, suggesting an uneven gait.
What are the different types of heel lift?
There are two main options. The right choice depends on the size of the correction you need and the type of shoes you wear.
In-shoe heel lift insole. A wedge placed inside your shoe, under the existing insole or built into a custom orthotic. Suitable for smaller corrections. Discreet and easy to move between shoes. Works well alongside orthotics and overpronation corrections if needed.
External shoe raise. Material is added to the sole of the shoe by a cobbler or orthotist. Used for larger corrections that would not fit comfortably inside the shoe. Less discreet but more stable for bigger differences.
How thick should a heel lift be?
The thickness of a heel lift should be based on a precise measurement of your leg length difference, not on a rough estimate. Your physiotherapist or podiatrist will decide the right amount. Several important principles guide that decision.
Gradual build-up
If you have had a leg length difference for years, your muscles, ligaments and joints have adapted. Adding the full correction all at once can feel uncomfortable and may even create new problems. Most clinicians start with a partial correction and increase it over weeks, giving your body time to adjust.
Full correction is not always the goal
Some people tolerate only a partial correction, and that is fine. The aim is to reduce symptoms and improve function, not to chase a perfect number on a scan. A trial period of a few weeks helps your clinician decide whether to increase, reduce or keep the lift at its current thickness.
Measurement accuracy matters
Even a small error in measuring the leg length difference can mean the lift is too thick or too thin. A lift that is too thick tilts the pelvis the wrong way. One that is too thin may not help at all. This is why getting an accurate, standing measurement before any lift is prescribed makes a real difference to the outcome.
Want to know your exact leg length difference before seeing your clinician? A standing EOS scan measures both legs under full body weight.
Book a free video consultationWhy does standing imaging give a better measurement for heel lifts?
Standing imaging gives a better measurement because it captures your skeleton under real-world loading. When you lie down for a standard X-ray, CT or MRI, gravity is removed and your muscles relax. Joints decompress slightly, and the pelvis can shift. The result can be a measurement that does not match how your body actually behaves on your feet.
ScanAlign standing EOS imaging takes a full-length image of both legs, the pelvis and the spine while you stand. This means the measurement reflects the difference your body actually experiences every time you walk. It also uses about 90% less radiation than a standard X-ray, around ten times less, so it is a low-dose option.
Your clinician can then use the standing measurement to prescribe a heel lift with confidence, knowing the figure reflects real loading. If the scan also shows a pelvic tilt or a spinal curve, that information helps them decide whether a lift alone is enough or whether other treatment is needed.
When MRI is the better tool. EOS shows bones, joints and alignment. If your clinician suspects a soft-tissue problem, such as a disc issue or nerve compression, MRI is usually the better choice. The two types of imaging answer different questions and can work well together.
Who is a heel lift right for, and when is it not the answer?
A heel lift is a simple intervention, but it is not suitable for everyone. Here is a general guide. Your clinician will make the final decision.
- Confirmed structural (true) leg length difference
- Lateral pelvic tilt linked to a shorter leg
- Persistent one-sided back, hip or knee pain with a measured discrepancy
- Post-surgical leg length change (e.g. after hip replacement)
- Functional (apparent) leg length difference caused by muscle tightness or pelvic rotation
- Pain that has no link to a measured discrepancy
- Guesswork without proper measurement
Frequently asked questions about heel lifts
No. You can self-refer. You can book a leg length measurement directly and bring the results to your own clinician.
You can, but it is risky. Off-the-shelf lifts come in set thicknesses that may not match your actual difference. An incorrect lift can tilt your pelvis the other way and create new problems.
It varies. Most people need a few weeks to adjust, especially if the lift is introduced gradually. Some feel an immediate improvement, while others notice changes over a month or more.
It can, if the back pain is related to a genuine leg length discrepancy and the resulting pelvic tilt. A lift is not a general back-pain remedy. It works by addressing a specific structural cause.
Yes. EOS uses about 90% less radiation than a standard X-ray, around ten times less. It is one of the lowest-dose skeletal imaging options available.
A structural (true) difference means one bone is genuinely shorter. A functional (apparent) difference means the bones are the same length but the legs appear unequal because of muscle tightness, pelvic rotation or joint position. A standing scan helps distinguish between the two.
Not necessarily. Many clinicians start with a partial correction and increase gradually. Full correction is sometimes the goal, but comfort and symptom relief matter more than matching a number exactly.
Yes. A heel lift can be built into a custom orthotic or placed underneath one. Your podiatrist can combine both corrections in a single device if needed.
Pricing details are on our FAQs and cost page.
No. ScanAlign is a diagnostic imaging clinic. We provide the accurate measurement your clinician needs to prescribe the right lift. The prescription itself comes from your physiotherapist, podiatrist or orthopaedic consultant.
Get an accurate leg length measurement first
A standing EOS scan measures both legs under real body weight, giving your clinician the precise figure they need to prescribe the right heel lift.
Book a free video consultationSources
- Knutson GA. Anatomic and functional leg-length inequality: a review and recommendation for clinical decision-making. Chiropractic & Osteopathy. 2005;13:11.
- Defrin R, Ben Benyamin S, Aldubi RD, Pick CG. Conservative correction of leg-length discrepancies of 10 mm or less for the relief of chronic low back pain. Archives of Physical Medicine and Rehabilitation. 2005;86(11):2075-2080.
- NHS. Back pain: causes. nhs.uk/conditions/back-pain.
Written by Abbas Dhami (Specialist Diagnostic Radiographer)
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.