title: Stance control knee mechanism for lower-limb support in hybrid neuroprosthesis.
abstract: A hydraulic stance control knee mechanism (SCKM) was developed to fully support the knee against flexion during stance and allow uninhibited motion during swing for individuals with paraplegia using functional neuromuscular stimulation (FNS) for gait assistance. The SCKM was optimized for maximum locking torque for body-weight support and minimum resistance when allowing for free knee motion. Ipsilateral and contralateral position and force feedback were used to control the SCKM. Through bench and nondisabled testing, the SCKM was shown to be capable of supporting up to 70 N-m, require no more than 13% of the torque achievable with FNS to facilitate free motion, and responsively and repeatedly unlock under an applied flexion knee torque of up to 49 N-m. Preliminary tests of the SCKM with an individual with paraplegia demonstrated that it could support the body and maintain knee extension during stance without the stimulation of the knee extensor muscles. This was achieved without adversely affecting gait, and knee stability was comparable to gait assisted by knee extensor stimulation during stance.
authors.affiliation: Louis Stokes Cleveland Department of Veterans Affairs Medical Center, OH, USA. cst@cwru.edu
authors.forename: Curtis S
authors.initials: CS
authors.lastname: To
authors.forename: Rudi
authors.initials: R
authors.lastname: Kobetic
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Bulea
authors.forename: Musa L
authors.initials: ML
authors.lastname: Audu
authors.forename: John R
authors.initials: JR
authors.lastname: Schnellenberger
authors.forename: Gilles
authors.initials: G
authors.lastname: Pinault
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Triolo
mesh_terms: D001696:Biomechanical Phenomena; D006801:Humans; D058542:Implantable Neurostimulators; D007717:Knee; D035002:Lower Extremity; D019736:Prostheses and Implants; D011474:Prosthesis Design; D013119:Spinal Cord Injuries / Q000534:rehabilitation*; D016138:Walking / Q000502:physiology