Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity

Abstract Gravity plays a crucial role in shaping patterned locomotor output to maintain dynamic stability during locomotion. The present study aimed to clarify the gravity-dependent regulation of modules that organize multiple muscle activities during walking in humans. Participants walked on a trea...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Shota Hagio, Makoto Nakazato, Motoki Kouzaki
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/bd08f19ad3ba4491ae9bf7af132abc92
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:bd08f19ad3ba4491ae9bf7af132abc92
record_format	dspace
spelling	oai:doaj.org-article:bd08f19ad3ba4491ae9bf7af132abc922021-12-02T16:26:37ZModulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity10.1038/s41598-021-94201-92045-2322https://doaj.org/article/bd08f19ad3ba4491ae9bf7af132abc922021-07-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-94201-9https://doaj.org/toc/2045-2322Abstract Gravity plays a crucial role in shaping patterned locomotor output to maintain dynamic stability during locomotion. The present study aimed to clarify the gravity-dependent regulation of modules that organize multiple muscle activities during walking in humans. Participants walked on a treadmill at seven speeds (1–6 km h−1 and a subject- and gravity-specific speed determined by the Froude number (Fr) corresponding to 0.25) while their body weight was partially supported by a lift to simulate walking with five levels of gravity conditions from 0.07 to 1 g. Modules, i.e., muscle-weighting vectors (spatial modules) and phase-dependent activation coefficients (temporal modules), were extracted from 12 lower-limb electromyographic (EMG) activities in each gravity (Fr ~ 0.25) using nonnegative matrix factorization. Additionally, a tensor decomposition model was fit to the EMG data to quantify variables depending on the gravity conditions and walking speed with prescribed spatial and temporal modules. The results demonstrated that muscle activity could be explained by four modules from 1 to 0.16 g and three modules at 0.07 g, and the modules were shared for both spatial and temporal components among the gravity conditions. The task-dependent variables of the modules acting on the supporting phase linearly decreased with decreasing gravity, whereas that of the module contributing to activation prior to foot contact showed nonlinear U-shaped modulation. Moreover, the profiles of the gravity-dependent modulation changed as a function of walking speed. In conclusion, reduced gravity walking was achieved by regulating the contribution of prescribed spatial and temporal coordination in muscle activities.Shota HagioMakoto NakazatoMotoki KouzakiNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-16 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Shota Hagio Makoto Nakazato Motoki Kouzaki Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
description	Abstract Gravity plays a crucial role in shaping patterned locomotor output to maintain dynamic stability during locomotion. The present study aimed to clarify the gravity-dependent regulation of modules that organize multiple muscle activities during walking in humans. Participants walked on a treadmill at seven speeds (1–6 km h−1 and a subject- and gravity-specific speed determined by the Froude number (Fr) corresponding to 0.25) while their body weight was partially supported by a lift to simulate walking with five levels of gravity conditions from 0.07 to 1 g. Modules, i.e., muscle-weighting vectors (spatial modules) and phase-dependent activation coefficients (temporal modules), were extracted from 12 lower-limb electromyographic (EMG) activities in each gravity (Fr ~ 0.25) using nonnegative matrix factorization. Additionally, a tensor decomposition model was fit to the EMG data to quantify variables depending on the gravity conditions and walking speed with prescribed spatial and temporal modules. The results demonstrated that muscle activity could be explained by four modules from 1 to 0.16 g and three modules at 0.07 g, and the modules were shared for both spatial and temporal components among the gravity conditions. The task-dependent variables of the modules acting on the supporting phase linearly decreased with decreasing gravity, whereas that of the module contributing to activation prior to foot contact showed nonlinear U-shaped modulation. Moreover, the profiles of the gravity-dependent modulation changed as a function of walking speed. In conclusion, reduced gravity walking was achieved by regulating the contribution of prescribed spatial and temporal coordination in muscle activities.
format	article
author	Shota Hagio Makoto Nakazato Motoki Kouzaki
author_facet	Shota Hagio Makoto Nakazato Motoki Kouzaki
author_sort	Shota Hagio
title	Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
title_short	Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
title_full	Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
title_fullStr	Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
title_full_unstemmed	Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
title_sort	modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/bd08f19ad3ba4491ae9bf7af132abc92
work_keys_str_mv	AT shotahagio modulationofspatialandtemporalmodulesinlowerlimbmuscleactivationsduringwalkingwithsimulatedreducedgravity AT makotonakazato modulationofspatialandtemporalmodulesinlowerlimbmuscleactivationsduringwalkingwithsimulatedreducedgravity AT motokikouzaki modulationofspatialandtemporalmodulesinlowerlimbmuscleactivationsduringwalkingwithsimulatedreducedgravity
_version_	1718384014541193216

Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity

Ejemplares similares