Holliston

This research aims to systematically evaluate two common assumptions about pattern recognition control for prosthetic arms in adults aged 18 years and older with upper limb loss at the transradial level. The study focuses on whether targeting specific muscle sites or increasing the number of myoelectric sensor channels beyond 4-6 improves functional use of a physical prosthesis. It tests these assumptions directly with participants controlling real prosthetic limbs during daily activities. Participants will use experimental sockets fitted with different configurations of myoelectric channels: 4 untargeted, 8 untargeted, up to 16 untargeted, and 8 targeted channels. Each participant will be randomly assigned to a sequence of these four conditions in a crossover design. In addition to the experimental sockets, participants will use a commercially available Coapt EMG Cuff at home, which connects to software for virtual training games. The study includes up to 5 in-lab sessions lasting about 4 hours each, with visits spaced 1-2 weeks apart. At each visit, participants will train with and test the assigned socket condition. During visits, participants will complete functional outcome measures such as the Assessment of Capacity for Myoelectric Control (ACMC) and other tests designed for upper limb prosthesis users. They will also play virtual games using the Coapt software at home to improve muscle control. Researchers will monitor participants throughout all sessions and allow breaks as needed. The study evaluates functional performance changes across the different channel configurations and collects self-reported experiences. Total participation spans multiple visits over several weeks with ongoing home-based training.