Lately, more and more techniques and technologies have emerged to assist certain operations, which has led to the emergence of devices specially designed for the rehabilitation of people with different degrees of disability. Especially in the case of amputated arms or if the patient has reduced mobility and control over the limbs, several types of devices have been designed.This book focuses on developing a device to facilitate arm movement because, after researching this type of devices, we noticed that most of them are focused on supporting or limiting arm movement in the recovery process, few of them having also the target of reducing the effort made by the arm to achieve the movement, despite the fact that most patients need this as well. The book is intended for students in System Control and Computer Engineering, but mostly for researchers in these fields.