Optimal workloop energetics of muscle-actuated systems: an impedance matching view.

Integrative approaches to studying the coupled dynamics of skeletal muscles with their loads while under neural control have focused largely on questions pertaining to the postural and dynamical stability of animals and humans. Prior studies have focused on how the central nervous system actively mo...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Waleed A Farahat, Hugh M Herr
Formato:	article
Lenguaje:	EN
Publicado:	Public Library of Science (PLoS) 2010
Materias:	Biology (General) QH301-705.5
Acceso en línea:	https://doaj.org/article/54eb10e9d5614e30b097ff52c1149f27
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:54eb10e9d5614e30b097ff52c1149f27
record_format	dspace
spelling	oai:doaj.org-article:54eb10e9d5614e30b097ff52c1149f272021-12-02T19:58:23ZOptimal workloop energetics of muscle-actuated systems: an impedance matching view.1553-734X1553-735810.1371/journal.pcbi.1000795https://doaj.org/article/54eb10e9d5614e30b097ff52c1149f272010-06-01T00:00:00Zhttps://www.ncbi.nlm.nih.gov/pmc/articles/pmid/20532203/?tool=EBIhttps://doaj.org/toc/1553-734Xhttps://doaj.org/toc/1553-7358Integrative approaches to studying the coupled dynamics of skeletal muscles with their loads while under neural control have focused largely on questions pertaining to the postural and dynamical stability of animals and humans. Prior studies have focused on how the central nervous system actively modulates muscle mechanical impedance to generate and stabilize motion and posture. However, the question of whether muscle impedance properties can be neurally modulated to create favorable mechanical energetics, particularly in the context of periodic tasks, remains open. Through muscle stiffness tuning, we hypothesize that a pair of antagonist muscles acting against a common load may produce significantly more power synergistically than individually when impedance matching conditions are met between muscle and load. Since neurally modulated muscle stiffness contributes to the coupled muscle-load stiffness, we further anticipate that power-optimal oscillation frequencies will occur at frequencies greater than the natural frequency of the load. These hypotheses were evaluated computationally by applying optimal control methods to a bilinear muscle model, and also evaluated through in vitro measurements on frog Plantaris longus muscles acting individually and in pairs upon a mass-spring-damper load. We find a 7-fold increase in mechanical power when antagonist muscles act synergistically compared to individually at a frequency higher than the load natural frequency. These observed behaviors are interpreted in the context of resonance tuning and the engineering notion of impedance matching. These findings suggest that the central nervous system can adopt strategies to harness inherent muscle impedance in relation to external loads to attain favorable mechanical energetics.Waleed A FarahatHugh M HerrPublic Library of Science (PLoS)articleBiology (General)QH301-705.5ENPLoS Computational Biology, Vol 6, Iss 6, p e1000795 (2010)
institution	DOAJ
collection	DOAJ
language	EN
topic	Biology (General) QH301-705.5
spellingShingle	Biology (General) QH301-705.5 Waleed A Farahat Hugh M Herr Optimal workloop energetics of muscle-actuated systems: an impedance matching view.
description	Integrative approaches to studying the coupled dynamics of skeletal muscles with their loads while under neural control have focused largely on questions pertaining to the postural and dynamical stability of animals and humans. Prior studies have focused on how the central nervous system actively modulates muscle mechanical impedance to generate and stabilize motion and posture. However, the question of whether muscle impedance properties can be neurally modulated to create favorable mechanical energetics, particularly in the context of periodic tasks, remains open. Through muscle stiffness tuning, we hypothesize that a pair of antagonist muscles acting against a common load may produce significantly more power synergistically than individually when impedance matching conditions are met between muscle and load. Since neurally modulated muscle stiffness contributes to the coupled muscle-load stiffness, we further anticipate that power-optimal oscillation frequencies will occur at frequencies greater than the natural frequency of the load. These hypotheses were evaluated computationally by applying optimal control methods to a bilinear muscle model, and also evaluated through in vitro measurements on frog Plantaris longus muscles acting individually and in pairs upon a mass-spring-damper load. We find a 7-fold increase in mechanical power when antagonist muscles act synergistically compared to individually at a frequency higher than the load natural frequency. These observed behaviors are interpreted in the context of resonance tuning and the engineering notion of impedance matching. These findings suggest that the central nervous system can adopt strategies to harness inherent muscle impedance in relation to external loads to attain favorable mechanical energetics.
format	article
author	Waleed A Farahat Hugh M Herr
author_facet	Waleed A Farahat Hugh M Herr
author_sort	Waleed A Farahat
title	Optimal workloop energetics of muscle-actuated systems: an impedance matching view.
title_short	Optimal workloop energetics of muscle-actuated systems: an impedance matching view.
title_full	Optimal workloop energetics of muscle-actuated systems: an impedance matching view.
title_fullStr	Optimal workloop energetics of muscle-actuated systems: an impedance matching view.
title_full_unstemmed	Optimal workloop energetics of muscle-actuated systems: an impedance matching view.
title_sort	optimal workloop energetics of muscle-actuated systems: an impedance matching view.
publisher	Public Library of Science (PLoS)
publishDate	2010
url	https://doaj.org/article/54eb10e9d5614e30b097ff52c1149f27
work_keys_str_mv	AT waleedafarahat optimalworkloopenergeticsofmuscleactuatedsystemsanimpedancematchingview AT hughmherr optimalworkloopenergeticsofmuscleactuatedsystemsanimpedancematchingview
_version_	1718375777825718272

Optimal workloop energetics of muscle-actuated systems: an impedance matching view.

Ejemplares similares