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Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves

Humans and animals control their walking rhythms to maintain motion in a variable environment. The neural mechanism for controlling rhythm has been investigated in many studies using mechanical and electrical stimulation. However, quantitative evaluation of rhythm variation in response to perturbati...

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Autores principales: Funato, Tetsuro, Yamamoto, Yuki, Aoi, Shinya, Imai, Takashi, Aoyagi, Toshio, Tomita, Nozomi, Tsuchiya, Kazuo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4874544/
https://www.ncbi.nlm.nih.gov/pubmed/27203839
http://dx.doi.org/10.1371/journal.pcbi.1004950
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author Funato, Tetsuro
Yamamoto, Yuki
Aoi, Shinya
Imai, Takashi
Aoyagi, Toshio
Tomita, Nozomi
Tsuchiya, Kazuo
author_facet Funato, Tetsuro
Yamamoto, Yuki
Aoi, Shinya
Imai, Takashi
Aoyagi, Toshio
Tomita, Nozomi
Tsuchiya, Kazuo
author_sort Funato, Tetsuro
collection PubMed
description Humans and animals control their walking rhythms to maintain motion in a variable environment. The neural mechanism for controlling rhythm has been investigated in many studies using mechanical and electrical stimulation. However, quantitative evaluation of rhythm variation in response to perturbation at various timings has rarely been investigated. Such a characteristic of rhythm is described by the phase response curve (PRC). Dynamical simulations of human skeletal models with changing walking rhythms (phase reset) described a relation between the effective phase reset on stability and PRC, and phase reset around touch-down was shown to improve stability. A PRC of human walking was estimated by pulling the swing leg, but such perturbations hardly influenced the stance leg, so the relation between the PRC and walking events was difficult to discuss. This research thus examines human response to variations in floor velocity. Such perturbation yields another problem, in that the swing leg is indirectly (and weakly) perturbed, so the precision of PRC decreases. To solve this problem, this research adopts the weighted spike-triggered average (WSTA) method. In the WSTA method, a sequential pulsed perturbation is used for stimulation. This is in contrast with the conventional impulse method, which applies an intermittent impulsive perturbation. The WSTA method can be used to analyze responses to a large number of perturbations for each sequence. In the experiment, perturbations are applied to walking subjects by rapidly accelerating and decelerating a treadmill belt, and measured data are analyzed by the WSTA and impulse methods. The PRC obtained by the WSTA method had clear and stable waveforms with a higher temporal resolution than those obtained by the impulse method. By investigation of the rhythm transition for each phase of walking using the obtained PRC, a rhythm change that extends the touch-down and mid-single support phases is found to occur.
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spelling pubmed-48745442016-06-09 Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves Funato, Tetsuro Yamamoto, Yuki Aoi, Shinya Imai, Takashi Aoyagi, Toshio Tomita, Nozomi Tsuchiya, Kazuo PLoS Comput Biol Research Article Humans and animals control their walking rhythms to maintain motion in a variable environment. The neural mechanism for controlling rhythm has been investigated in many studies using mechanical and electrical stimulation. However, quantitative evaluation of rhythm variation in response to perturbation at various timings has rarely been investigated. Such a characteristic of rhythm is described by the phase response curve (PRC). Dynamical simulations of human skeletal models with changing walking rhythms (phase reset) described a relation between the effective phase reset on stability and PRC, and phase reset around touch-down was shown to improve stability. A PRC of human walking was estimated by pulling the swing leg, but such perturbations hardly influenced the stance leg, so the relation between the PRC and walking events was difficult to discuss. This research thus examines human response to variations in floor velocity. Such perturbation yields another problem, in that the swing leg is indirectly (and weakly) perturbed, so the precision of PRC decreases. To solve this problem, this research adopts the weighted spike-triggered average (WSTA) method. In the WSTA method, a sequential pulsed perturbation is used for stimulation. This is in contrast with the conventional impulse method, which applies an intermittent impulsive perturbation. The WSTA method can be used to analyze responses to a large number of perturbations for each sequence. In the experiment, perturbations are applied to walking subjects by rapidly accelerating and decelerating a treadmill belt, and measured data are analyzed by the WSTA and impulse methods. The PRC obtained by the WSTA method had clear and stable waveforms with a higher temporal resolution than those obtained by the impulse method. By investigation of the rhythm transition for each phase of walking using the obtained PRC, a rhythm change that extends the touch-down and mid-single support phases is found to occur. Public Library of Science 2016-05-20 /pmc/articles/PMC4874544/ /pubmed/27203839 http://dx.doi.org/10.1371/journal.pcbi.1004950 Text en © 2016 Funato et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Funato, Tetsuro
Yamamoto, Yuki
Aoi, Shinya
Imai, Takashi
Aoyagi, Toshio
Tomita, Nozomi
Tsuchiya, Kazuo
Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves
title Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves
title_full Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves
title_fullStr Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves
title_full_unstemmed Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves
title_short Evaluation of the Phase-Dependent Rhythm Control of Human Walking Using Phase Response Curves
title_sort evaluation of the phase-dependent rhythm control of human walking using phase response curves
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4874544/
https://www.ncbi.nlm.nih.gov/pubmed/27203839
http://dx.doi.org/10.1371/journal.pcbi.1004950
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