Ankle Foot Orthosis
Indicated as a low profile option for rehabilitation of ankle sprains and minor fractures of the ankle and foot. Offers less support and stability than other options such as a CAM walker or AFO but provides a lower profile and therefore more cosmetic option. The amount of support and the design materials will vary depending on the exact brace that is chosen.
Examples include the following Arizona Brace.
Total Surface Bearing/Thermoplastic is always preferable due to increased control areas and the reduced pressures on the skin that results. Therefore, the total surface bearing orthoses provide more comfort and better function than the conventional alternative. Total Surface Bearing/Thermoplastic designs are also considerably lighter, have a better durability/weight ratio, are easier to clean, and can easily be chance to different shoes.
Conventional AFOs can be a valuable tool, however, they are generally a last resort behind Total Surface Bearing/Thermoplastic or hybrid designs. Conditions that merit their use include conditions with fluctuating edema or fluid retention, or patient preference.
Conditions with fluctuating edema or fluid retention
Heat sensitivity – as seen occasionally with Multiple Sclerosis (thermoset or carbon braces are also an option)
Patient’s leg can not be casted or scanned – can only be traced or measured (very rare).
Stirrups make changing shoes difficult
Accommodates fluxuating edema better than total contact designs.
Only requires a tracing of the leg and measurements in order to fabricate.
Higher pressures on the skin due to forces being applied to a relatively small surface area.
Less control is available due to reduced surface area.
Joints and uprights tend to be heavy
Control of the foot relies on the shoe.
Any time significant changes in volume are not anticipated
When significant changes in volume are anticipated
Reduces pressures on the skin
High durability/weight ratio
Easy to clean/ hygienic
Can easily be changed to different shoes.
Does not accommodate for changes in volume as well as conventional systems
Same functions as solid AFO in frontal plane.
In the sagittal plane, provides significant knee extension moment during weight bearing/stance phase.
This can be an excellent alterative to a KAFO design for patients with trace or weak quadriceps in that it can achieve knee stability while maintaining efficiency by reducing weight and bulkiness.
Note – Articulated designs may help in allowing for more normal step length/gait by not unnecessarily blocking plantarflexion.
Often used with Crouch Gait.
When significant deweighting of the ankle and foot is required.
Typically used for:
Painful conditions of the heel
Problems with ulceration
Conditions of skin and peripheral circulation which can not tolerate the pressure of the PTB.
Unstable knee joint
The C.R.O.W. is a combination of an ankle foot othosis and a custom boot. The C.R.O.W. was developed for patients with severe charcot changes of the foot and ankle where a more traditional means of treatment was not satisfactory. The device is in essence a bivalved copolymer full foot enclosure ankle foot orthosis with a rocker bottom sole built on the device.
The orthosis is fully lined with a custom foot insert and custom formed to a plastic impression of the patients affected limb. Appropriate modifications are performed to the impression, which permits for equal weight distribution through the limb and foot. The C.R.O.W. can be modified within limits to accommodate changes by flaring, adding padding and trimming where and when appropriate. It is very useful in protecting the patient from further breaks but not 100% as patients can and do fracture in plastic and fiberglass casts.
The C.R.O.W. is easy to don and doff. Patients can bathe daily and maintain proper hygiene. Many patients learn to drive with the C.R.O.W. Over all the acceptance is good due to availability of colors in the copolymers. The ability to bathe and sleep with freedom from a cast makes the C.R.O.W. a great asset.