Exploiting Selective Recruitment to Prolong Standing After SCI

Neuroprostheses for standing after SCI currently rely on continuous activation of the hip and knee extensor muscles, which results in rapid fatigue and ultimately compromises elapsed standing time. The primary objective of this study is to improve the performance of neuroprostheses for standing by developing and implementing advanced stimulation paradigms that use multi-contact peripheral nerve electrodes to delay fatigue onset and prolong standing duration. The new stimulation paradigms will take advantage of the ability of multi-contact nerve cuff electrodes to selectively activate independent portions of a muscle, or independent muscles that perform the same action. Such a capability will allow one or more muscles (or parts of the same muscle) to rest while the others continue to contract to keep the knee extended and the user upright. Stimulation waveforms that alternate activation to multiple muscles performing the same function, rather than continuously activate the entire muscle group constantly, should allow muscles to rest and recover from fatiguing contractions.

In addition to these important clinical benefits, the project is also of high impact and significance because the methods to be developed will not be specific to any single electrode technology or stimulation system. Any clinical or therapeutic application that requires a sustained muscular contraction or the production of constant joint torques for prolonged periods of time will benefit from the successful completion of this project.