Restoration of Upper Extremity Function in Tetraplegia

Electrical stimulation of the peripheral nervous system has been utilized to provide functional control of the upper extremity in cervical level spinal cord injury. An implanted neuroprosthesis utilizing electrical stimulation has received Food and Drug Administration approval and is available for implementation in clinical practice. This neuroprosthesis provides for two basic hand grasps under user control and is governed by a sensor that is generally worn on the opposite shoulder. Use of the system enables independent performance of activities of daily living. A second-generation technology is currently under human investigation that provides for finer control of grasp, control of the forearm and elbow, and more natural control governed by the user's ipsilateral extremity. Advanced concepts are under development that record afferent activity to regulate grasp and that use cortical signals to provide the control input.