This thesis presents a novel hand exosuit for rehabilitation and assistance in Spinal Cord Injuries (SCI). The developed prototype was designed with three distinctive features: a) the actuation of the exoskeleton is based on four-tendon model, which simulate the four groups of tendons inside fingers; b) all its components are compact on the back of the hand without taking up space on the patient's forearm, this allows the portability of the device and makes it suitable for personal patient assistance; c) its finger motion units are composed of a series of flexible open rings and a thimble on the fingertips all crossed by four cables for the actuation, this makes the units modular and adjustable according to the length of the patient's fingers. The design and development were carried out at the PERCRO laboratories of the Scuola Superiore Sant'Anna. A first characterization of the prototype was carried out on the basis of grasping force and grasping pressure. Then, a preliminary experimentation was carried out at the Careggi Hospital in Florence on some patients suffering from SCI with motor disabilities in the hands
