a portable medical device suitable for use in continuous passive motion rehabilitation programs has a lightweight modular frame for ease of storage and portability . in one embodiment a proximal sling module is pivotally connected to a distal sling module with is pivotally connected to a heal plate module . another embodiment includes a base module is pivotally connected to a proximal sling module which is pivotally connected to a distal sling module pivotally connected to a link pivotally connected to the base . the joint of a patient &# 39 ; s limb is flexed through a range of motion by pivoting the distal sling module relative to the proximal sling module . the device is powered by a motor and worm gear directed by a controller .