Types of Ankle Foot Orthosis

Austin Foot and Ankle Specialists offer several types of ankle foot orthosis also referred to as an AFO. The most commonly prescribed AFO's are the hinged AFO, Fixed AFO and Gauntlet-Style AFO. Austin Foot and Ankle Specialists will assess you thorougly to find the best prescribed AFO for you. Typically the most common factor to assess your need for an AFO is mobility vs non-mobility. Dr. Thomajan typically utilizes a Gauntlet-Style AFO for immobilization.

 

What is an AFO?

An AFO (Ankle Foot Orthosis) is a plastic splint that can be worn to support your foot and ankle in a better posture for walking or standing.

 

What does an AFO do?

• Improve walking and mobility in every day life
• Allow smoother walking and transfers
• Reduce fatigue associated with walking
• Help prevent tripping when walking
• Improve balance
• Limit movement at the foot and ankle joints which is often needed to improve walking pattern
• Provide support for unstable ankles
• Maintain the best ankle and foot position especially where increased muscle tone is present
• Some AFOs have a special design to help keep the knee straight when walking – this is called a GRAFO (ground reaction ankle foot orthosis)

 

What is a Hinged AFO?

The hinged AFO is in many ways very similar to the fixed ankle type. During the manufacture of the hinged AFO a simple mechanical joint is fitted at the level of the ankle axis and incorporated into the moulding. A backstop is also fitted behind the ankle to prevent plantarflexion (toe walking). This AFO design is a custom-made hinged ankle foot orthosis for support and stabilization of the talocalcaneal, mid-tarsal, and subtalar joints. These AFO’s manage abnormal motion or severe pronation in the transverse and frontal planes. It also stabilizes the ankle area medially, laterally, and reduces either forefoot abduction or adduction.

 

 

What is a Fixed AFO?

The fitting of a solid (fixed) AFO can be very effective at preventing a toe-walking gait as well as sideways movements of the ankle (Valgus & Varus movements). Solid AFOs can be used very effectively in providing stability and encouraging a good base of support. Solid AFOs are also used where an existing contracture (muscle or tendon shortening) already exists and may not have any ankle movement present.

 

 

 

What is a Gauntlet AFO?

Gauntlet style AFO's are often times more flexible braces. Often times patient are unable to DON a hinged or fixed brace. Gauntlet AFO's are an ideal conservative treatment for many common ankle conditions, the most popular being posterior tibial dysfunction (PTTD) and arthritis. For patients with these painful conditions, the gauntlet-style AFO is used to reduce ambulation pain, maintain foot and ankle position, and reduce the progression of deformity over time. One of the additional benefits of gauntlet-style AFO's is wearability in conjuction with durability. The trim lines, flex of material and reduction of bulkiness compared to walker boots or more rigid AFO's provide a different sense of comfort that makes long-term use of a gauntlet more plausible. Additionally, there are different material options that can be selected, making the AFO a better candidate to produce improved patient outcomes. Material selections can affect anything from volume to increases of mobilization (while maintaining stability), as well as friction of the device on the skin - a pertinent concern for diabetics.

 

 

Design Criteria

Whatever types of orthoses are recommended or fitted, they share many common design points and try to provide some or all of the elements below:

•hind foot stability (close moulding around heel)
•mid-forefoot stability (medial & lateral extensions, good arch support)
•control of unwanted exaggerated and abnormal movements
•reduction of the effects of increased tone (spasticity)
•promotion of a stable base
•encouragement of good standing position with equal weight bearing on both feet.
•toe and Metatarsal support (tone management)
•contoured sole plates to assist in foot stabilisation (tone reduction)
•construction from semi flexible or rigid materials (polypropylene, polythene etc)

 

 

Contact us today with any questions or to schedule your AFO casting.