title: Paraplegic standing supported by FES-controlled ankle stiffness.
abstract: The objective of this paper was to investigate whether a paraplegic subject is able to maintain balance during standing by means of voluntary and reflex activity of the upper body while being supported by closed loop controlled ankle stiffness using FES. The knees and hips of the subject were held in extended positions by a mechanical apparatus, which restricted movement to the sagittal plane. The subject underwent several training sessions where the appropriate level of stiffness around the ankles was maintained by the mechanical apparatus. This enabled the subject to learn how to use the upper body for balancing. After the subject gained adequate skills closed-loop FES was employed to regulate ankle stiffness, replacing the stiffness provided by the apparatus. A method to control antagonist muscle moment was implemented. In subsequent standing sessions, the subject had no difficulties in maintaining balance. When the FES support was withheld, the ability to balance was lost.
authors.affiliation: Centre for Systems and Control, University of Glasgow, Glasgow, G12 8QQ, Scotland, U.K. ralf-peter.jaime@de.bosch.com
authors.forename: Ralf-Peter
authors.initials: RP
authors.lastname: Jaime
authors.forename: Zlatko
authors.initials: Z
authors.lastname: Matjacić
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Hunt
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology*; D004548:Elasticity; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005246:Feedback; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008954:Models, Biological; D009132:Muscles / Q000503:physiopathology*; D009989:Orthotic Devices; D010264:Paraplegia / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation*; D004856:Postural Balance; D011187:Posture; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013119:Spinal Cord Injuries / Q000150:complications / Q000534:rehabilitation; D013904:Thoracic Vertebrae / Q000293:injuries; D014836:Volition