Ankle foot orthotics may be custom made by a podiatrist or prescribed and made by a licensed orthotist prosthetist. There are non-custom or prefabricated ankle foot orthotics too which can be used depending on the nature of the problem being treated. Healthcare professionals trained in this field do not use guess work to determine the best device but make such choices based on a complete examination of the patient. Such exams generally involve a biomechanical exam of the foot, ankle and leg to determine gait, muscle strength, posture, the condition of joints, ligaments and tendons.
Custom ankle foot orthotics, like custom foot orthotics, start with a mold made of the foot as well as the ankle. The podiatrist determines the optimal position of the ankle and joints of the foot during the molding process. An accredited orthotic laboratory uses the mold and presription information to create a working model of the foot and ankle which is used to build the AFO around.


There are three ligaments on the outside of the ankle that help maintain proper alignment of the ankle joint and prevent ankle sprains: the ATF or anterior talofibular ligament, the PTF or posterior talofibular ligament and the CFL or calcaneofibular ligament.  The ankle ligaments can become damaged, stretched or torn due to a significant ankle sprain or even a series of smaller sprains.  That can lead to an ankle that feels weak, painful and twists easily.
Treatments for lateral ankle instability include physical therapy, surgical repair or ankle foot orthotics.

The ankle joint is designed to go up and down (dorsiflexion/plantarflexion), not side to side.  Side to side motion of the foot comes from the joint immediately below the ankle, the subtalar joint.   Ankle joints may become painful and arthritic for a number of reasons including osteoarthritis, trauma such as severe ankle sprains and fracture and even chronic repetitive type injuries.  Dr. Ed Davis has treated a number of retired airborne warriors who developed ankle pain years after leaving the military....repetitive jumps leaving damaged ankle cartilage.
Joints which operate within their physiologic limits, that is, within their normal functional range do better than when additional loads or strain is placed on them.  The ankle joint is generally happy to go up and down but becomes painful when there is excessive side to side motion or torsional strain.  Ankle foot orthotics can be designed to minimize side to side motion and torsional strain at the ankle joint.
Dropfoot occurs when the muscles that lift the foot up with each step are weak or not working.  That may occur after a stroke or damage to the nerves controlling the muscles or muscle damage itself.  Dropfoot makes it difficult to walk as one cannot lift the foot and the toes may drag on the ground, get caught and cause loss of balance. There are two categories of AFO or ankle foot orthotics that may be used for dropfoot.
1)  Fixed ankle type AFO:  This may be a prefabricated plastic brace which holds up the foot or a custom one depending on the needs of the patient.  Such AFOs are generally used acutely or if there is no upward muscle strength at the ankle or if muscle strenght is not expected to recover.
2)  Dorsiflexion assist type AFO:  This type of ankle foot orthotic is generally custom and includes a foot portion that looks similar to many custom foot orthoticss.  The foot portion or foot "plate" is joined to the ankle portion by flexible hinges that are spring loaded.  Patients who have partial muscle power or who are expected to gain muscle strength are best served by such devices.