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Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability
It has been observed that times series of gait parameters [stride length (SL), stride time (ST), and stride speed (SS)], exhibit long-term persistence and fractal-like properties. Synchronizing steps with rhythmic auditory stimuli modifies the persistent fluctuation pattern to anti-persistence. Anot...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3759806/ https://www.ncbi.nlm.nih.gov/pubmed/24027529 http://dx.doi.org/10.3389/fphys.2013.00230 |
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author | Terrier, Philippe Dériaz, Olivier |
author_facet | Terrier, Philippe Dériaz, Olivier |
author_sort | Terrier, Philippe |
collection | PubMed |
description | It has been observed that times series of gait parameters [stride length (SL), stride time (ST), and stride speed (SS)], exhibit long-term persistence and fractal-like properties. Synchronizing steps with rhythmic auditory stimuli modifies the persistent fluctuation pattern to anti-persistence. Another non-linear method estimates the degree of resilience of gait control to small perturbations, i.e., the local dynamic stability (LDS). The method makes use of the maximal Lyapunov exponent, which estimates how fast a non-linear system embedded in a reconstructed state space (attractor) diverges after an infinitesimal perturbation. We propose to use an instrumented treadmill to simultaneously measure basic gait parameters (time series of SL, ST, and SS from which the statistical persistence among consecutive strides can be assessed), and the trajectory of the center of pressure (from which the LDS can be estimated). In 20 healthy participants, the response to rhythmic auditory cueing (RAC) of LDS and of statistical persistence [assessed with detrended fluctuation analysis (DFA)] was compared. By analyzing the divergence curves, we observed that long-term LDS (computed as the reverse of the average logarithmic rate of divergence between the 4th and the 10th strides downstream from nearest neighbors in the reconstructed attractor) was strongly enhanced (relative change +73%). That is likely the indication of a more dampened dynamics. The change in short-term LDS (divergence over one step) was smaller (+3%). DFA results (scaling exponents) confirmed an anti-persistent pattern in ST, SL, and SS. Long-term LDS (but not short-term LDS) and scaling exponents exhibited a significant correlation between them (r = 0.7). Both phenomena probably result from the more conscious/voluntary gait control that is required by RAC. We suggest that LDS and statistical persistence should be used to evaluate the efficiency of cueing therapy in patients with neurological gait disorders. |
format | Online Article Text |
id | pubmed-3759806 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-37598062013-09-11 Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability Terrier, Philippe Dériaz, Olivier Front Physiol Physiology It has been observed that times series of gait parameters [stride length (SL), stride time (ST), and stride speed (SS)], exhibit long-term persistence and fractal-like properties. Synchronizing steps with rhythmic auditory stimuli modifies the persistent fluctuation pattern to anti-persistence. Another non-linear method estimates the degree of resilience of gait control to small perturbations, i.e., the local dynamic stability (LDS). The method makes use of the maximal Lyapunov exponent, which estimates how fast a non-linear system embedded in a reconstructed state space (attractor) diverges after an infinitesimal perturbation. We propose to use an instrumented treadmill to simultaneously measure basic gait parameters (time series of SL, ST, and SS from which the statistical persistence among consecutive strides can be assessed), and the trajectory of the center of pressure (from which the LDS can be estimated). In 20 healthy participants, the response to rhythmic auditory cueing (RAC) of LDS and of statistical persistence [assessed with detrended fluctuation analysis (DFA)] was compared. By analyzing the divergence curves, we observed that long-term LDS (computed as the reverse of the average logarithmic rate of divergence between the 4th and the 10th strides downstream from nearest neighbors in the reconstructed attractor) was strongly enhanced (relative change +73%). That is likely the indication of a more dampened dynamics. The change in short-term LDS (divergence over one step) was smaller (+3%). DFA results (scaling exponents) confirmed an anti-persistent pattern in ST, SL, and SS. Long-term LDS (but not short-term LDS) and scaling exponents exhibited a significant correlation between them (r = 0.7). Both phenomena probably result from the more conscious/voluntary gait control that is required by RAC. We suggest that LDS and statistical persistence should be used to evaluate the efficiency of cueing therapy in patients with neurological gait disorders. Frontiers Media S.A. 2013-09-03 /pmc/articles/PMC3759806/ /pubmed/24027529 http://dx.doi.org/10.3389/fphys.2013.00230 Text en Copyright © 2013 Terrier and Dériaz. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Physiology Terrier, Philippe Dériaz, Olivier Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
title | Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
title_full | Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
title_fullStr | Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
title_full_unstemmed | Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
title_short | Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
title_sort | non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability |
topic | Physiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3759806/ https://www.ncbi.nlm.nih.gov/pubmed/24027529 http://dx.doi.org/10.3389/fphys.2013.00230 |
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