Abstract: To make a foot orthotic device shaped to correct the plantar surface of a patient's foot from an appropriately shaped body, that body is made by taking measurements of various characteristics of the patient's foot directly from that foot, including measurements of various aspects of the patient's arch, generating a model of the plantar surface of the foot from these measurements, then modifying this model in accordance with a practitioner's corrective prescription, and using those modified measurements to control a shaping device such as a milling machine to produce on said body a three-dimensional surface constituting the desired corrected shape for the patient's plantar surface.