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dc.contributor.authorGregg, Robert D.
dc.contributor.authorRouse, Elliott Jay
dc.contributor.authorHargrove, Levi J.
dc.contributor.authorSensinger, Jonathon W.
dc.date.accessioned2014-04-30T19:50:16Z
dc.date.available2014-04-30T19:50:16Z
dc.date.issued2014-02
dc.date.submitted2013-07
dc.identifier.issn1932-6203
dc.identifier.urihttp://hdl.handle.net/1721.1/86302
dc.description.abstractHuman locomotion is a rhythmic task in which patterns of muscle activity are modulated by state-dependent feedback to accommodate perturbations. Two popular theories have been proposed for the underlying embodiment of phase in the human pattern generator: a time-dependent internal representation or a time-invariant feedback representation (i.e., reflex mechanisms). In either case the neuromuscular system must update or represent the phase of locomotor patterns based on the system state, which can include measurements of hundreds of variables. However, a much simpler representation of phase has emerged in recent designs for legged robots, which control joint patterns as functions of a single monotonic mechanical variable, termed a phase variable. We propose that human joint patterns may similarly depend on a physical phase variable, specifically the heel-to-toe movement of the Center of Pressure under the foot. We found that when the ankle is unexpectedly rotated to a position it would have encountered later in the step, the Center of Pressure also shifts forward to the corresponding later position, and the remaining portion of the gait pattern ensues. This phase shift suggests that the progression of the stance ankle is controlled by a biomechanical phase variable, motivating future investigations of phase variables in human locomotor control.en_US
dc.description.sponsorshipUnited States Army Medical Research Acquisition Activity (USAMRAA grant W81XWH-09-2-0020)en_US
dc.description.sponsorshipNational Institute of Neurological Disorders and Stroke (U.S.) (NIH award number F31NS074687)en_US
dc.description.sponsorshipBurroughs Wellcome Fund (Career Award at the Scientific Interface)en_US
dc.language.isoen_US
dc.publisherPublic Library of Scienceen_US
dc.relation.isversionofhttp://dx.doi.org/10.1371/journal.pone.0089163en_US
dc.rightsCreative Commons Attributionen_US
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en_US
dc.sourcePLoSen_US
dc.titleEvidence for a Time-Invariant Phase Variable in Human Ankle Controlen_US
dc.typeArticleen_US
dc.identifier.citationGregg, Robert D., Elliott J. Rouse, Levi J. Hargrove, and Jonathon W. Sensinger. “Evidence for a Time-Invariant Phase Variable in Human Ankle Control.” Edited by Manabu Sakakibara. PLoS ONE 9, no. 2 (February 18, 2014): e89163.en_US
dc.contributor.departmentProgram in Media Arts and Sciences (Massachusetts Institute of Technology)en_US
dc.contributor.mitauthorRouse, Elliott Jayen_US
dc.relation.journalPLoS ONEen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsGregg, Robert D.; Rouse, Elliott J.; Hargrove, Levi J.; Sensinger, Jonathon W.en_US
mit.licensePUBLISHER_CCen_US


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