The general nature and function of the AFO has been presented. These devices encompass the foot and leg crossing the ankle joint. They may insert into the shoe or attach to the shoe. The more recent AFOs are made of polypropylene and were formerly composed of steel. The indications for an AFO are for a basically ambulatory patient with problems walking, including various pathologic gaits especially drop-foot and spastic equinus. Other primary indications include ankle arthritis, Charcot foot, fractures, and post-surgery. Given the basic employment of AFOs to treat problems directly related to the foot, it is hoped that this introduction has stimulated practitioners to begin using this essential tool as an integral component of their practice.