Musculoskeletal modeling for intrafacicular multielectrode stimulation of the feline hindlimb

Spinal cord injuries result in a loss of control of the muscles and organs innervated by the nerves below the level of the injury and can have a significant impact on the quality of life for the individuals affected. Functional electrical stimulation (FES) techniques have provided a way, via neural prosthetics, to regenerate limited control of the musculoskeletal system for persons with spinal cord injuries. Intrafascicular multielectrode stimulation (IFMS) is a form of functional electrical stimulation which utilizes penetrating electrodes such as the Utah Slanted Electrode Array. This array has 100 electrodes which are inserted into the nerve and provide selective control of muscles innervated by the peripheral nervous system. Before IFMS or FES can be used to restore muscle control for spinal cord injury patients, the muscles which are to be stimulated must be selected and stimulation paradigms must be determined. By using a musculoskeletal model in conjunction with numerical simulations, muscle activation paradigms can be determined for a given behavior. Additionally, muscle subsets (which can be selectively stimulated instead of the full set of available muscles) can be explored parametrically.