A shoulder end range of motion improving device has a linkage, the linkage including a first link member, a second link member supported on the first link member, the second link member configured for being secured to an arm of a patient and being rotatable about a second link axis for rotating the arm of the patient about a shoulder joint of the patient through an arm range of motion, the second link axis being displaceable into a selectable fixed position, the fixed position being maintained during rotation of the second link member, an actuator for rotating the second link member about the second link axis, and a controller controlling the actuator for selectively rotating the second link member about the second link axis through the arm range of motion.