To understand how AFOs work, one must first understand two standard motions that occur at the ankle joint – “dorsiflexion” and “plantarflexion”. Plantarflexion is the motion the ankle joint makes when the toes point downward. Dorsiflexion is the motion the ankle joint makes when the foot points upward. This motion needs to occur when the foot comes off the ground so that the patient does not drag their toes. Patients with dropfoot usually have a partial or complete weakness of the muscles that dorsiflex the foot at the ankle joint.
Sometimes carbon graphite devices that provide some ground reaction energy return are used for drop foot. This is curious since most cases of drop foot do not include corresponding plantar flexion weakness. Like an energy-storing prosthetic foot, the benefit of these carbon graphite AFOs is that the spring is compressed by body weight as the tibia travels over the foot. Then, late in stance phase, the energy is released by the material the brace is composed of and returned for use in toe-off. This energy return may be desirable for the flail foot, but the typical drop foot case does not need this feature.
ASSOCIATED CONDITIONS
Drop foot
Peroneal nerve injury
Posterior tibial tendon dysfunction
Ankle sprains, strains
Tendonitis
Lateral ankle instability
Flatfoot
Arthritis
Polio
Charcot-Marie-Tooth
Charcot joint
Cerebral palsy
Muscular dystrophy
Tibial or fibular fracture
Amyotrophic lateral sclerosis
WEARING PROTOCOL
Your physician and your certified orthotist will give specific instructions as to your particular protocol, but normally the brace is to be worn when active and ambulating if a functional design.
DON AND DOFF
This design should be placed in a shoe and the foot slipped into the brace securely.
CARE
Normally, alcohol on a clean cloth can be used.