 Our investigator initiated feasibility trial seeks to test the Activa PCS as a therapeutic system to restore movement to paralyzed muscles. Our mission is to develop and demonstrate in humans innovative direct neural interface technology that restores motor function, rehabilitates, and improves the quality of life of individuals with SCI. Investigators seek to enable testing that will lead to innovative neuroprosthetic therapies that improve recovery by retraining the nervous system, reduce secondary conditions, and create a better life for persons with SCI and other conditions that impair physical or cognitive function. This project will increase the understanding and tempo of research into the modes of functionality of a fully implantable system from the following perspectives: neurosurgery, biomedical engineering, rehabilitation, and therapeutics. A major strength of our approach is that it incrementally tests sub-components of the system through a systematic buildup of functionality towards control of upper extremity function. 