An ankle-foot orthotic device is designed to closely simulate the natural movement of a lower extremity throughout a proper walking gait cycle. The orthotic device includes upper and lower support members that are pivotally coupled by opposing dorsiflexion assist members. The lower support member includes a rigid, unitary cup for receiving the heel and ankle portions of the lower extremity. The cup is shaped to include a continuous slot that allows for at least 5 degrees of compression upon initial heel strike and thereby promotes a smooth, decelerating heel roll. The lower support member additionally includes a rigid footplate on which is mounted a flexible overlay, the overlay extending beyond the footplate in the medial aspect to promote proper pronation into midstance. A compressible stop is mounted on the lower support member and selectively contacts the upper support member to prevent hyperextension of the lower extremity.
