This CAREER grant focuses on the development and evaluation of novel computational tools to predict changes in human movement with exoskeletons. Recent technological advances have created new exoskeletons, external devices including orthoses and braces, which can apply passive or active torques to the human body. However, the ability of these devices to make consistent improvements in movement remains challenging. A fundamental knowledge gap exists in how the human body responds and adapts when wearing these devices, hindering performance and development. To overcome this gap, this research will use a combination of musculoskeletal simulation and experimental motion capture to create a conceptual framework for modeling and predicting changes in neuromuscular control and musculoskeletal dynamics when wearing devices that apply assistive, augmentive, or preventive torques to the human body. Two model systems that apply external torques to the ankle will be used to experimentally test and evaluate this framework: passive ankle foot orthoses for assisting movement and active ankle orthoses for enhancing power. These systems will be tested with individuals with stroke or cerebral palsy who commonly use orthoses to improve movement, as well as unimpaired individuals. Prior simulations of human movement have largely focused on the musculoskeletal system, but few techniques exist to model neuromuscular control and muscle recruitment. Dynamic simulation provides an ideal framework to specify and test different neuromuscular control strategies and expand our ability to design optimized exoskeletons. This research will develop algorithms to model neuromuscular control with dynamic simulation, predict changes in human movement with exoskeletons, and experimentally evaluate this new framework. All algorithms developed will be shared in an open-source simulation framework, OpenSim, for other researchers and educators to use.
The proposed research will provide the foundation to improve movement for individuals with neurological disorders, such as cerebral palsy and stroke, and others who can benefit from advances in wearable technology. The technical advances in algorithm development and neuromuscular simulation will provide a new set of tools for researchers and clinicians to use in the design, evaluation, and prescription of devices to enhance human movement. To help train engineers who can apply their knowledge to the complexities of the human body, a multidisciplinary education program focused on human engineering will be created at the University of Washington for students in engineering and medicine. Students will participate in journal clubs, coursework, and design projects where they will create open-source orthoses for individuals with disabilities. We will also develop open-source outreach modules focused on human engineering in partnership with local programs that encourage under-represented groups to pursue careers in engineering, including women, minorities, and individuals with disabilities. These modules will be shared on-line for other groups to use and help encourage a diverse community of future engineers. Together this work will help to accelerate the design and prescription of exoskeletons for individuals with neurological disorders and promote a community passionate about enhancing the performance of the ultimate machine - the human body.
