Abstract: A portable device for articulating a person's foot relative to the person's lower leg. A first embodiment of the device includes a pair of opposing cast portions configured to conformably fit around the person's lower leg. A pair of frame members are each connected to one of the cast portions and extend below the lower ends of the cast portions. A foot support plate is pivotally connected to the lower ends of the frame members. Detachable straps are secured in surrounding relationship about the cast portions and frame members for holding the cast portions around the person's lower leg with the foot resting on the foot support plate. A motor mechanism and a connecting rod reciprocate the foot support plate and the foot carried thereby relative to the person's lower leg. A second embodiment has selectively extensible longitudinal frame members which are laterally adjustable relative to a leg surrounding U-shaped motor mount.