Posterior leaf spring AFO
Draft — clinical review requiredA flexible AFO with a narrow posterior strip that bends during stance and springs back in swing.
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: A flexible strip resists foot drop before contact.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
- Narrow posterior strip behind the calf and under the foot.
Joints crossed
- Ankle and foot.
Movements it may allow, resist or constrain
- Resists plantarflexion in swing; allows some dorsiflexion in stance.
Intended functional goals
- Foot clearance with flexible stance motion.
Potential applications
- Isolated dorsiflexor weakness with adequate stance control — after assessment.
Limitations, tradeoffs and precautions
- Limited mediolateral control.
- Not suited to marked spasticity or instability.
Individual assessment and fitting
- Stiffness of the strip, tone, and stance stability.
- 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 posterior leaf spring AFO is least suited to…
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 Posterior leaf spring AFO sits and which joints it crosses.
- Explain which movements it may allow, resist or constrain.
- List factors that require individual assessment and fitting.