People with Duchenne Muscular Dystrophy, especially those with severe muscle weakness (Brooke Scale 4), still lack access to suitable arm supports. Due to variations among the population, it is hard to find a one-size-fits-all solution. Additionally, achieving an initiative human-exoskeleton interaction with strong but compact actuation that fits the limited design space is technologically challenging. This thesis will guide you through the steps we took to develop our prototype, the Duchenne ARm ORthosis (DAROR). Starting with formulating the design requirements, exploring different control strategies, and verifying these strategies within the realized hardware, including custom-made actuators. Through this work, we hope to bridge the gap in current solutions and advance the development of effective arm supports that can greatly improve the quality of life and help those still waiting for the right technology.