Knee-ankle-foot orthosis (KAFO)
A class of orthosis that crosses the knee joint and extends from the thigh to the foot, configured individually for knee stability, lower limb alignment and gait control.
What is a KAFO?
A KAFO (knee-ankle-foot orthosis) is a lower limb orthosis that covers the knee, ankle and foot together. The structure begins at the thigh, crosses the knee joint and extends down to the foot section. The person's own leg is preserved; because the KAFO supports this anatomical structure from the outside, it is not a prosthesis.
Its main difference from an AFO (ankle-foot orthosis) is that it also controls the knee joint. It is considered in situations where knee stability is insufficient, where the leg needs to be controlled during weight-bearing, or where the aim is to manage ankle and knee alignment together.
What parts does a KAFO consist of?
A KAFO is not a single part or a single mechanism. The thigh and calf contact sections, the knee joint, the load-bearing side bars, ankle control, the foot section and the straps are combined according to the person's anatomy and goals.
- Thigh section and load-bearing structure
- Mechanical or electronically controlled knee joint
- Calf connections and ankle section
- Footplate, shoe attachment and fastening elements
Types of KAFO by knee joint control
While the anatomical class remains the same, the way the knee mechanism works can differ. The choice is made according to safety, muscle strength, joint movement, manual dexterity and daily goals.
KAFO with a locked knee joint
A mechanical structure intended to keep the knee joint locked while standing and walking. To sit down, the lock may need to be released by the user or a helper.
Stance-control KAFO
A mechanical or electronic system that aims to provide knee stability during the stance phase and, if conditions are suitable, to allow knee movement during the swing phase.
Microprocessor-controlled KAFO
An electronically controlled system that uses sensor data to regulate knee resistance during the different phases of gait.
Learn moreSuitability assessment
The decision on a KAFO is not made on the basis of the diagnosis alone; whether the device can be used safely and the likelihood of a functional benefit are assessed together.
Knee stability
Whether the knee gives way forward or backward under load or buckles involuntarily, and the person's ability to control this, are examined.
Hip and trunk control
The proximal control needed to advance the leg, keep balance and use a walking aid is assessed.
Joint movement
Range of motion at the hip, knee and ankle, as well as fixed contractures, can affect the design options.
Muscle strength and tone
Muscle weakness, fatigue, spasticity and involuntary muscle activity are addressed together.
Sensation, skin and circulation
Because of the risk of pressure and friction along the long contact line, skin integrity is assessed closely.
Cognitive and hand functions
The ability to operate the lock, put the system on correctly and follow safety instructions is important in the choice.
Distinguishing KAFO, AFO and HKAFO
An AFO covers the ankle and foot; a KAFO adds the knee joint and thigh section. A long system that also crosses the hip joint is called an HKAFO (hip-knee-ankle-foot orthosis). An HKAFO is not just a longer model of a KAFO; it is a separate anatomical scope that also includes hip control.
Seeing a metal joint at the knee does not always mean that a microprocessor is used. The joint may be locked, free, mechanically stance-controlled, electronically stance-controlled or continuously resistance-adjusted by a microprocessor.
- AFO: ankle + foot
- KAFO: knee + ankle + foot
- HKAFO: hip + knee + ankle + foot
The KAFO fitting and training process
Clinical and functional assessment
Muscle strength, joint movement, balance, skin, sensation, history of falls and daily goals are examined.
Measurement and choice of mechanism
The contact sections, knee and ankle joints, locking system and foot section are planned individually.
Trial and alignment
Mechanical axes, pressure areas and the fit with the shoe are checked while standing, sitting and walking.
Gait training
Training is given on using the lock, sitting down and standing up, using a walking aid, stepping safely and dealing with falls.
Periodic follow-up
The joint mechanisms, straps, skin contact and changes in body measurements are checked regularly.
Frequently asked questions
Is a KAFO the same as a knee brace?
No. A knee brace may support only the area around the knee. A KAFO, by contrast, begins at the thigh and extends to the foot, crossing the knee and ankle; it controls more than one joint together.
Does everyone who uses a KAFO keep their knee locked?
No. The knee joint may be permanently locked, free, stance-controlled or microprocessor-controlled. The suitable mechanism is selected through individual assessment.
Can stairs be used with a KAFO?
This depends on the joint mechanism, muscle strength, balance, use of a walking aid and environmental conditions. The safe method should be practiced with the rehabilitation team.
This content is for information purposes; it does not replace a diagnosis or an individual device recommendation. The KAFO fitting is planned in line with a specialist physician's assessment and prescription/medical report.
