A method and apparatus for providing a topographical map of the bottom of a patient's rear foot with the foot in a semi-weight bearing condition and in the neutral position. A flexible membrane defines the top of an air cushion that captures the patient's foot in the neutral position when the air pillow is inflated. The membrane also conforms to the bottom of the foot. A three-dimensional scanner located below the membrane measures the distances to the bottom of the membrane over an array of positions. A manufacturing facility converts these measurements into information by which computer numerical controlled equipment machines an orthotic insert for the patient's footwear.