A CASE STUDY OF CAPACITIES AND LIMITATIONS RELATED TO ARTHROGRYPOSIS MULTIPLEX CONGENITA AND COMPUTER INTERFACES
Authors: Wayne Shebilske and Jennifer Border
Abstract: We describe Arthrogryposis Multiplex Congenita (AMC), the presence of multiple joint contractures at birth, and we analyze the capacities and limitations of the second author, Jennifer Border, who has this condition. In AMC, the joints (arthro) of hands, wrists, elbows, shoulders, hips, feet, and knees are often fixed in a curved (gryp) position. Characteristically, the thumbs are pinned in the palms, and the hands are bent toward the arms, which are turned toward the body. Range of motion is limited by these joint contractures and often by muscle weakness. The purpose of analyzing capacities and limitations is to lay a foundation for human-centered assistive technologies especially computer interfaces. Determining an optimal interface for Jennifer is timely because her physicians have asked her to stop using a stylus held in her mouth, which has been her main interface with computer keyboards. Jennifer developed a repetitive motion injury in her shoulders from frequent use of this interface throughout grade school, high school, college, and her current first year in a Human Factors Psychology graduate program. This injury is affecting not only her interface with computers, but also other important tasks such as preparing and eating meals for which she is heavily reliant on her shoulder muscles. To prepare meals, for example, she holds containers in her mouth and pours by tilting her head and shoulders. In order to maintain these essential abilities, she must find an alternative computer interface and work station. Alternative interfaces under consideration are voice, eye movements, and EMG signals from facial muscles. Preliminary evaluations of these alternatives and their combinations will be made, but the present focus will be on analyzing Jenniferís capacities and limitations as a step toward a human-centered final choice.