Duchenne muscular Dystrophy (DMD) Is a progressive muscle degenerative disease. Active hand assistive devices, can improve the quality of life of people with DMD. Such devices show a rejection rate due to complexity. Our hypothesis is, that a simple orthosis might prove more functional and realistic in assisting people with DMD. To investigate, we developed a portable setup that provides various visual stimuli and records the response of the subjects' fingers through a mouse clicking task. Six LEDs served as visual stimuli. The subjects' responses were obtained through mechanical interaction with two vertical mice. Different combinations of frequencies and numbers of stimuli were tested with 8 healthy subjects and one with DMD. Performance was evaluated in terms of information transfer rate (ITR), pattern accuracy and perceived workload. The outcome shows that lower complexity results in lower ITR and lower workload for all subjects. While for healthy subjects, maximum ITR was 4.3 bits/s, for DMD maximum ITR was 2.5 bits/s. Both maxima were achieved at the same trial (3 fingers at 2 Hz). This trial agrees with a pareto optimization analysis of ITR with respect to workload. The results support our hypothesis for a simple yet functional solution. Furthermore healthy subjects and the individual with DMD, in principal show similar finger control, albeit with lower absolute performance.