Ankle-foot orthosis (AFO)
A class of orthoses that covers the ankle and foot together and is configured individually to support the position of the foot and certain phases of walking.
What is an AFO?
AFO (ankle-foot orthosis) is the general name for orthoses that cover the ankle and foot. The person's own leg is preserved; the orthosis supports this anatomical structure from the outside. For this reason, an AFO is not a prosthesis.
The aim is to guide or limit ankle movement, help reduce the foot catching during the swing phase, support alignment during the stance phase and, when necessary, manage indirect effects on the knee. The same AFO is not suitable for every user; stiffness, height, joint structure and the foot section are selected according to the clinical assessment.
Which region does an AFO cover?
The upper limit of an AFO is at the calf; the structure crosses the ankle joint and extends to the sole of the foot. It does not include the knee joint. A system that also crosses the knee joint belongs anatomically to the KAFO (knee-ankle-foot orthosis) class.
- Calf section: allows the orthosis to hold onto the lower leg.
- Ankle section: can leave movement free, limit it or guide it.
- Foot section: is shaped according to the position of the heel, sole and forefoot.
Main AFO designs
These classes are not entirely mutually exclusive. Material, joint structure and stiffness can be combined in different ways for the same person.
Fixed or rigid AFO
Designed to markedly limit ankle movement and hold the foot in the targeted position.
Articulated AFO
Aims to allow movement in certain directions with the help of a mechanical joint or flexible zone while controlling the other directions.
Dynamic AFO
Designed to provide controlled movement or energy return during the step through the flexibility and geometry of the material.
Learn moreWhat is considered in the assessment?
The choice of AFO is not made solely on the basis of the name of the diagnosis or the appearance of the product.
Muscle strength
The muscles that move the ankle up and down are assessed together with the muscles that contribute to knee control.
Joint movement
The passive and active range of motion of the ankle and fixed deformities are examined.
Muscle tone
Spasticity, involuntary muscle activity and rapidly changing characteristics of movement may affect the design.
Knee control
Although an AFO does not cover the knee joint, the ankle angle may affect the behavior of the knee during the stance phase.
Skin and sensation
Pressure risk, circulation, loss of sensation and skin integrity are taken into account in the plan of use.
Footwear and activity
The internal volume of the shoe, the sole structure and the person's daily level of activity are considered together.
AFOs in children
In children, an AFO may be considered to support foot and ankle alignment and to contribute to standing and walking goals. Because growth is ongoing, measurements, fit, skin checks and duration of use are reviewed more frequently.
The orthosis design is planned together with the child's motor skills, muscle tone, joint movement, the shoes they wear and therapy goals.
- Changes in fit due to growth are monitored.
- Redness and pressure areas are checked regularly.
- Orthosis use is planned together with therapy and daily activities.
The AFO fitting process
Clinical assessment
Diagnosis, muscle strength, joint movement, skin, sensation and walking are examined together.
Design and measurement
The stiffness, height, joint characteristics and foot section of the orthosis are determined and measurements are taken.
Trial and alignment
Contact areas, fit with footwear and effects during walking are checked.
Training and follow-up
Putting on and taking off, skin checks, cleaning and gradual use are explained; check-ups are planned.
Frequently asked questions
What is the main difference between an AFO and a KAFO?
An AFO covers the ankle and foot and does not cross the knee joint. A KAFO, on the other hand, covers the knee, ankle and foot together and includes a control component for the knee joint.
Is the same AFO used for every case of foot drop?
No. The cause of foot drop, joint movement, muscle tone, knee control, skin and daily activities change the choice of design.
Can an AFO be used without shoes?
Many AFOs are designed to be used together with suitable shoes for safe load transfer and to prevent slipping. The manner of use is explained by the team carrying out the fitting.
This content is for information purposes only; it does not replace a diagnosis or an individualized device recommendation. Orthosis fitting is planned in line with a specialist physician's assessment and prescription/medical report.
