An aid device for the movement and rehabilitation hand fingers includes a exoskeleton, an articulated glove or a wearable mechanism configured to be positioned on the back of at least one finger and to be mechanically constrained to the finger, and a motorized system exerting a movement or a change in the configuration of the exoskeleton. The exoskeleton includes a rigid elements arranged on a row one behind the other along a longitudinal axis parallel to the longitudinal extension of the finger and articulated with each other to make a modular underactuated structure and obtain maximum shape and kinematic adaptability to the fingers, particularly to follow the extension and flexing movement of the fingers. The motorized system includes pulling and/or pushing elements that act on one or more of the elements of the exoskeleton to produce finger movements and particularly the extension and flexing movements of the fingers.