Orthotic names can sound like alphabet soup. If you are comparing AFO vs SMO, or you have just heard the letters KAFO for the first time, you are not alone. This short explainer gives plain-language meanings and shows why the differences matter when you shop for shoes.
This article is general information, written for families and caregivers. It is not medical advice. Your doctor, physiotherapist or orthotist decides which type of orthosis is right, and only they can describe how it is designed to work for your child or for you.
Why the letters matter
Each set of letters tells you which parts of the body the orthosis covers. "Orthosis" simply means a device that supports or aligns part of the body. The letters are a shorthand: for example, A stands for ankle, F for foot, K for knee. Once you know that, the names start to make sense.
For daily life, the length and shape of the orthosis changes things such as:
- how it is put on and taken off,
- how much space it takes up inside a shoe,
- the kind of shoe opening that is practical,
- and how clothing sits over it.
AFO: ankle-foot orthosis
AFO stands for ankle-foot orthosis. It generally covers the foot and extends up the lower leg, so it supports the ankle and foot. It is worn inside a shoe, and it is one of the most commonly discussed types of leg braces for children and adults.
AFOs come in different designs, from more rigid to more flexible, and they can be ready-made or custom-made. Your orthotist chooses the design based on their clinical assessment. If you would like a fuller introduction, see our guide on what an AFO is.
SMO and KAFO in brief
SMO stands for supramalleolar orthosis. The word "supramalleolar" refers to the area just above the ankle bones. An SMO generally covers the foot and the area around the ankle, and is usually shorter than an AFO. It is also worn inside a shoe, and it is often described as a lower-profile option.
KAFO stands for knee-ankle-foot orthosis. As the name says, it includes the knee as well as the ankle and foot, and usually extends higher up the leg. It is a larger device, and it can involve additional parts at the knee.
A simple way to picture the differences, from shortest to longest:
| Orthosis | Stands for | Generally covers |
|---|---|---|
| SMO | Supramalleolar orthosis | Foot and the area around the ankle |
| AFO | Ankle-foot orthosis | Foot, ankle and lower leg |
| KAFO | Knee-ankle-foot orthosis | Foot, ankle, lower leg and knee |
This table is a simplification. Real devices vary a lot in design and fit, so please use it only as a general guide. Other types of leg braces exist too, and your orthotist can explain which terms apply.
What changes for shoe choice
The orthosis lives inside the shoe, so the shoe needs room for it. Some general points:
- Space. The more of the foot and ankle an orthosis covers, the more internal room may be needed. It is usual for families to need a larger size, a wider fit, or extra depth.
- Opening. A wide opening, such as one created by a zipper that opens the shoe fully, can make it easier to place the foot and orthosis inside.
- Insoles. Removable insoles can make extra depth available, and some people use them together with their orthotist's advice.
- Closure. Think about who will put the shoe on and how.
- Try with the device. Always try shoes on with the orthosis in place.
We want to be honest here: shoes that are described as AFO-friendly are designed with these needs in mind, but we do not claim that any shoe fits every AFO, SMO or KAFO. Fit depends on the individual device and foot. Please check with your orthotist, and message us if you would like to talk through the measurements.
You can learn more about the features we look at in what makes a shoe AFO-friendly, and browse our AFO-friendly collection.
Talk to your orthotist
Your orthotist is the best person to explain your device. Some questions you might bring:
- Which type of orthosis is this, and what does each part do?
- How many hours should it be worn each day?
- What should I look for in a shoe, and are there features I should avoid?
- How often should it be checked as we grow or as things change?
- How should I care for it, and what signs should prompt me to call you?
Writing the answers down can be helpful when you are choosing shoes. If you would like us to help you interpret measurements, you can contact us.
Frequently asked questions
What does KAFO mean?
KAFO stands for knee-ankle-foot orthosis, a device that includes the knee, ankle and foot. Your orthotist can explain how it is designed for you.
Is an SMO the same as an AFO?
No. They are different terms for devices that generally cover different areas. An SMO is usually shorter and focuses on the foot and the area around the ankle, while an AFO extends higher up the lower leg.
Which shoe should I buy for my orthosis?
Only your orthotist can advise on this. Tell us the type of orthosis and your measurements, and we can help you explore options. Try shoes on with the device before you decide.
Need help choosing?
Start with our AFO-friendly collection, or contact us with any questions. Delivery is free in the UAE on orders above AED 500, and unworn items can be returned within 14 days.