: Design Modification, Fabrication, Construction and Performance Evaluation of a Prototype Body Mounted Upper Extremity Orthosis

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atrc, assistive, technology, resource, center, graduate, thesis, muscular, dystrophy, mechanical, arm, orthosis, orthoses, upper, body, mounted, mount


The goal of this MQP was to design an upper extremity orthosis with four degrees of freedom that would allow for shoulder flexion, shoulder abduction, humeral rotation, and elbow flexion. In some musculoskeletal diseases such as Duchenne Muscular Dystrophy (DMD), skeletal muscle groups progressively degenerate, with the most proximal groups degenerating first, and the most distal groups degenerating last. Teenagers with DMD often retain fine motor control in their hands, but do not have enough arm strength to allow them to use their hands. Current robotic assistive devices and arm supports often have a limited range of motion and can be difficult to control. Therefore, there is the need for an upper extremity orthosis that can optimize the user’s range of motion and allow for maximal use of their existing muscle functions. A previous design project at WPI (Felice and Smith, 1999) created the concept idea of a body-mounted arm orthosis, which could be mounted directly onto the body of the individual instead of the wheelchair. In the new design, pin joints at the shoulder ring and at the elbow joint allow for shoulder abduction and elbow flexion, respectively. The prototypes allows a user to perform daily tasks such as grooming, feeding, and reaching for, picking up, and manipulating objects by activating switches on the device. Testing of this passive prototype indicated that if powered, the orthosis would allow the user to perform eight basic daily living tasks by activating a sequence of switches. Though the device was designed specifically for users with DMD, it also has the potential to be useful for individuals with other forms of muscular dystrophy, spinal cord injuries, and stroke. This project was published in the Proceedings of the 2002 Annual RESNA Conference.