Custom foot orthotics (CFOs) and ankle-foot orthotics (AFOs) are both devices designed to support and correct lower extremity issues, but they differ significantly in their structure, purpose, and applications.The biomechanics practitioner is commonly confronted in difficult cases into deciding which type of device is most effective. Here's a comparison:
Custom Foot Orthotic (CFO)
- Definition: A custom-molded device designed to fit inside a shoe, providing support to the foot's arch, heel, or overall structure with the intention of improving biomechanical efficiency.
- Purpose:
- Alleviate foot pain caused by conditions like plantar fasciitis, bunions, over pronation of the feet, or excessive supination of the feet. Often effective to treat leg, knee, hip and lower back issues.
- Correct abnormal gait or biomechanics by redistributing pressure and aligning the foot.
- Provide support and cushioning for daily activities or sports.
- Construction: Typically made from materials like plastic, foam, or carbon fiber, shaped to the patient’s foot through molds or digital scans.
- Scope of Support: Targets the foot only, but also extends support to the ankle or leg.
- Use Cases: Ideal for addressing foot-specific issues or mild to moderate alignment problems affecting the lower extremity.
Ankle-Foot Orthotic (AFO)
- Definition: A brace that supports both the foot and ankle, extending up to the lower leg.
- Purpose:
- Stabilize the ankle joint for conditions like foot drop, spasticity, or ankle instability.
- Prevent or correct more severe deformities caused by injury, neurological or musculoskeletal conditions such as cerebral palsy, stroke, or multiple sclerosis.
- Assist with mobility and alignment for conditions like Charcot-Marie-Tooth disease or post-surgery recovery.
- Construction: Usually made of rigid or semi-rigid materials like plastic or carbon fiber; some models allow for joint articulation.
- Scope of Support: Provides structural support to both the foot and ankle, sometimes extending higher to control leg movement.
- Use Cases: Ideal for more severe biomechanical, neurological, or muscular conditions requiring control and stabilization beyond the foot.
Key Differences
|
Feature |
Custom Foot Orthotic (CFO) |
Ankle-Foot Orthotic (AFO) |
|
Area Supported |
Foot only, usually bilateral |
Foot and ankle (sometimes lower leg), usually unilateral |
|
Conditions Treated |
Foot pain, arch issues, mild to moderate gait related biomechanical issues |
Neurological/musculoskeletal conditions, injuries, instability |
|
Materials |
Flexible to rigid materials |
Rigid/semi-rigid materials |
In summary, CFOs are primarily used for foot-specific issues, and address the relationship between the foot and the weight bearing surface only, but have an effect on function and structure above the foot and ankle.. AFOs provide broader support and are essential for conditions that affect the relationship between the weight bearing surface and the foot in addition to the relationship between the foot and the ankle and lower leg, which generally requires greater stabilization. A CFO is more of a corrective device, whereas an AFO is more of a protective brace. Some AFOs, such as a Richie Brace offer both biomechanical correction as well as bracing.
Many factors must be weighed when deciding to use either a CFO or AFO. Additionally, the choice of what type of CFO or AFO must be made. Is the symptomatology limited to the foot or does it extend higher up the kinetic chain? Can functionality be achieved without protective bracing? Is there deformity or weakness present, and is it reducible or fixed deformity? Future posts will address the thought process involved in determining the best course of action regarding CFO versus AFO.
