Extrinsic rearfoot posts.

The addition of an extrinsic rearfoot post to an orthotic device allows the podiatric practitioner to modify the function of the device. Specifically, rearfoot posts are used to allow for a more inverted heel position at contact, to provide greater resistance to abnormal frontal plane motion of the calcaneus and to provide for motion for shock absorption. The authors present nine prescription variables that each provide for a specific functional change to be incorporated into the orthotic device.