Abstract: An apparatus having an elongated base from the proximal end of which a reclining patient's leg is extended to an elevated connection of the foot with a foot rest. Mechanism is provided for moving the foot rest so that the hip and knee may be mobilized to the exclusion of the ankle or vice-versa, by applying forces similar to those applied manually by a physiotherapist. This mechanism translates the longitudinal reciprocal stroke of a motor driven carriage into a combination longitudinal and arcuate motion of the foot rest. The foot rest is mounted on the upper end of an actuating arm whose lower end has a pivotal connection with a carriage movable along the base, in linear strokes, toward and from the proximal end.