In rehabilitation, the proper use of robotic devices offers significant advantages in both safety and treatment effectiveness. Correct use specifically includes accurate positioning of the user on the device to prevent misalignments that could result in discomfort or pain, and isolation of the movement to the intended body segment to avoid compensation strategies with other joints. This paper presents the design and development of an innovative wrist alignment and locking system implemented on the EDUSA® PRO robotic rehabilitation device. The proposed mechanism enables automatic centering of the human joint, aligning the user’s axes with those of the robot, and securely maintains the wrist position throughout the rehabilitation session. Additionally, it automatically adapts to different wrist sizes and user anthropometric characteristics, making it suitable for a wider range of individuals. The ergonomic design ensures comfort, ease of use, and safety, while the modularity of the system allows for application to other joints. These features help reduce setting errors by therapists and contribute to greater effectiveness and reliability of the rehabilitation process.