The Aircast AirHeel Ankle Support Brace treats plantar fasciitis, Achilles tendonitis, and heel pain by applying pulsating compression with every step, which helps reduce swelling and enhance circulation. The medial/lateral stabilizers offer enhanced proprioception and stability. It's designed with 2 interconnected air cells, located under the foot arch and in back of the Achilles tendon. When you take a step, the first air chamber (under the arch) begins to collapse, thus reducing the stress to the plantar fascia under the arch. Air is then forced into the chamber surrounding the Achilles tendon, which in turn inflates. The inflated Achilles chamber applies compression to the Achilles tendon to shorten the lever arm, therefore reducing strain on the tendon.