A device for increasing the range of motion of a patients knee joint comprising of a longitudinal track frame, having a sitting platform at one end and a movable leg and foot platform at the other end, driven back and forth by a foot actuation mechanism in a flexion-extension motion, linearly along the longitudinal track by an electronically controlled motor in accordance with user defined settings and operable in a passive, active or resistive mode in either a supine or sitting position.