Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals

Abstract Muscle synergy analysis is useful for investigating trunk coordination patterns based on the assumption that the central nervous system reduces the dimensionality of muscle activation to simplify movement. This study aimed to quantify the variability in trunk muscle synergy during various t...

Full description

Bibliographic Details
Main Authors: Hiroki Saito, Hikaru Yokoyama, Atsushi Sasaki, Kazuya Matsushita, Kimitaka Nakazawa
Format: Article
Language:English
Published: Nature Portfolio 2023-01-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-023-28467-6
_version_ 1797945929704144896
author Hiroki Saito
Hikaru Yokoyama
Atsushi Sasaki
Kazuya Matsushita
Kimitaka Nakazawa
author_facet Hiroki Saito
Hikaru Yokoyama
Atsushi Sasaki
Kazuya Matsushita
Kimitaka Nakazawa
author_sort Hiroki Saito
collection DOAJ
description Abstract Muscle synergy analysis is useful for investigating trunk coordination patterns based on the assumption that the central nervous system reduces the dimensionality of muscle activation to simplify movement. This study aimed to quantify the variability in trunk muscle synergy during various trunk motor tasks in healthy participants to provide reference data for evaluating trunk control strategies in patients and athletes. Sixteen healthy individuals performed 11 trunk movement and stability tasks with electromyography (EMG) recording of their spinal and abdominal muscles (6 bilaterally). Non-negative matrix factorization applied to the concatenated EMG of all tasks identified the five trunk muscle synergies (W) with their corresponding temporal patterns (C). The medians of within-cluster similarity defined by scalar products in W and rmax coefficient using the cross-correlation function in C were 0.73–0.86 and 0.64–0.75, respectively, while the inter-session similarities were 0.81–0.96 and 0.74–0.84, respectively. However, the lowest and highest values of both similarity indices were broad, reflecting the musculoskeletal system’s redundancy within and between participants. Furthermore, the significant differences in the degree of variability between the trunk synergies may represent the different neural features of synergy organization and strategies to overcome the various mechanical demands of a motor task.
first_indexed 2024-04-10T21:03:55Z
format Article
id doaj.art-1a69a67661fd484680e2138abb9a90f9
institution Directory Open Access Journal
issn 2045-2322
language English
last_indexed 2024-04-10T21:03:55Z
publishDate 2023-01-01
publisher Nature Portfolio
record_format Article
series Scientific Reports
spelling doaj.art-1a69a67661fd484680e2138abb9a90f92023-01-22T12:08:52ZengNature PortfolioScientific Reports2045-23222023-01-0113111210.1038/s41598-023-28467-6Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individualsHiroki Saito0Hikaru Yokoyama1Atsushi Sasaki2Kazuya Matsushita3Kimitaka Nakazawa4Department of Life Sciences, Graduate School of Arts and Sciences, The University of TokyoInstitute of Engineering, Tokyo University of Agriculture and TechnologyDepartment of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka UniversityAobadai Takeda OrthopedicDepartment of Life Sciences, Graduate School of Arts and Sciences, The University of TokyoAbstract Muscle synergy analysis is useful for investigating trunk coordination patterns based on the assumption that the central nervous system reduces the dimensionality of muscle activation to simplify movement. This study aimed to quantify the variability in trunk muscle synergy during various trunk motor tasks in healthy participants to provide reference data for evaluating trunk control strategies in patients and athletes. Sixteen healthy individuals performed 11 trunk movement and stability tasks with electromyography (EMG) recording of their spinal and abdominal muscles (6 bilaterally). Non-negative matrix factorization applied to the concatenated EMG of all tasks identified the five trunk muscle synergies (W) with their corresponding temporal patterns (C). The medians of within-cluster similarity defined by scalar products in W and rmax coefficient using the cross-correlation function in C were 0.73–0.86 and 0.64–0.75, respectively, while the inter-session similarities were 0.81–0.96 and 0.74–0.84, respectively. However, the lowest and highest values of both similarity indices were broad, reflecting the musculoskeletal system’s redundancy within and between participants. Furthermore, the significant differences in the degree of variability between the trunk synergies may represent the different neural features of synergy organization and strategies to overcome the various mechanical demands of a motor task.https://doi.org/10.1038/s41598-023-28467-6
spellingShingle Hiroki Saito
Hikaru Yokoyama
Atsushi Sasaki
Kazuya Matsushita
Kimitaka Nakazawa
Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
Scientific Reports
title Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
title_full Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
title_fullStr Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
title_full_unstemmed Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
title_short Variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
title_sort variability of trunk muscle synergies underlying the multidirectional movements and stability trunk motor tasks in healthy individuals
url https://doi.org/10.1038/s41598-023-28467-6
work_keys_str_mv AT hirokisaito variabilityoftrunkmusclesynergiesunderlyingthemultidirectionalmovementsandstabilitytrunkmotortasksinhealthyindividuals
AT hikaruyokoyama variabilityoftrunkmusclesynergiesunderlyingthemultidirectionalmovementsandstabilitytrunkmotortasksinhealthyindividuals
AT atsushisasaki variabilityoftrunkmusclesynergiesunderlyingthemultidirectionalmovementsandstabilitytrunkmotortasksinhealthyindividuals
AT kazuyamatsushita variabilityoftrunkmusclesynergiesunderlyingthemultidirectionalmovementsandstabilitytrunkmotortasksinhealthyindividuals
AT kimitakanakazawa variabilityoftrunkmusclesynergiesunderlyingthemultidirectionalmovementsandstabilitytrunkmotortasksinhealthyindividuals