Orthoses

Solid AFO

Draft — clinical review required

A rigid AFO that blocks ankle motion in both directions.

Without vs with the device — same illustrative patient and walking speedStoryboard — animation pending
Foot clearance

Toes may catch in swing when the ankle cannot dorsiflex.

Mechanism: The orthosis resists plantarflexion during swing.
Ankle position at contact

Flat or toes-first contact is possible.

Mechanism: Ankle is held in a fixed position.
Tibial progression

Tibia advances freely or is limited by tone.

Mechanism: Stiffness and alignment determine how much the tibia can move over the foot.
Knee behaviour

Depends on ankle and muscle control.

Mechanism: Changing ankle motion alters the ground reaction force line relative to the knee.

Qualitative only — possible changes, not predicted angles or effectiveness. Stiffness, alignment, footwear, available range, strength and motor control all influence the response.

Go deeper

Open each part when you are ready.

Where it sits
  • Posterior shell along the calf and under the foot.
Joints crossed
  • Ankle and foot.
Movements it may allow, resist or constrain
  • Blocks dorsiflexion and plantarflexion (depending on trimlines and material).
Intended functional goals
  • Maximal ankle stability.
  • Clearance in swing.
  • Control of tibial position, which can affect the knee.
Potential applications
  • Marked weakness or instability where ankle motion must be controlled — after assessment.
Limitations, tradeoffs and precautions
  • No ankle motion: affects rockers, push-off, stairs, slopes and sit-to-stand.
  • Pressure areas.
Individual assessment and fitting
  • Ankle angle setting, footwear heel height and tuning with the orthotist.
  • Response depends on stiffness, alignment, footwear, available range, strength and motor control. No device produces the same result in every patient.
What additional information would you need before considering this device?
  • Range of motion at the ankle, knee and hip.
  • Strength and motor control.
  • Tone and spasticity.
  • Sensation and skin integrity.
  • Footwear, goals, cognition and ability to don/doff.
  • Who will review fit and response over time.

Apply it

A solid AFO mainly affects which task beyond walking on level ground?

Open the Movement LabA device comparison model is not yet supported; the Movement Lab shows typical walking only.

Sources and review status

Draft — clinical review required

Starting points for verification. Validated protocols are linked where available; clinical content has not yet been reviewed.

Learning objectives
  • Identify where a Solid AFO sits and which joints it crosses.
  • Explain which movements it may allow, resist or constrain.
  • List factors that require individual assessment and fitting.
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