Speed-dependent modulation of muscle activity based on muscle synergies during treadmill walking

Benio Kibushi, Shota Hagio, Toshio Moritani, Motoki Kouzaki

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The regulation of walking speed is easily achieved. However, the central nervous system (CNS) must coordinate numerous muscles in order to achieve a smooth and continuous control of walking speed. To control walking speed appropriately, the CNS may need to utilize a simplified system for the control of numerous muscles. Previous studies have revealed that the CNS may control walking via muscle synergies that simplify the control of muscles by modularly organizing several muscles. We hypothesized that the CNS controls the walking speed by flexibly modulating activation of muscle synergies within one gait cycle. Then, we investigated how the activation of muscle synergies depend on walking speeds using the center of activity (CoA) that indicates the center of the distribution of activation timing within one gait cycle. Ten healthy men walked on a treadmill at 14 different walking speeds. We measured the surface electromyograms (EMGs) and kinematic data. Muscle synergies were extracted using non-negative matrix factorization. Then, we calculated the CoA of each muscle synergy. We observed that the CoA of each specific synergy would shift as the walking speed changed. The CoA that was mainly activated during the heel contact phase (C1) and the activation that contributed to the double support phase (C3) shifted to the earlier phase as the walking speed increased, whereas the CoA that produced swing initiation motion (C4) and the activation that related to the late-swing phase (C5) shifted to the later phase. This shifting of the CoAindicates that the CNScontrols intensive activation of muscle synergies during the regulation of walking speed. In addition, shifting the CoA might be associated with changes in kinematics or kinetics depending on the walking speed. We concluded that the CNSflexibly controls the activation of muscle synergies in regulation of walking speed.

Original languageEnglish
Article number4
JournalFrontiers in Human Neuroscience
Volume12
DOIs
Publication statusPublished - 2018 Jan 24
Externally publishedYes

Fingerprint

Walking
Muscles
Central Nervous System
Gait
Biomechanical Phenomena
Walking Speed
Heel
Electromyography

Keywords

  • Center of activity
  • Central nervous system
  • Electromyograms
  • Joint acceleration
  • Motor control
  • Non-negative matrix factorization

ASJC Scopus subject areas

  • Neuropsychology and Physiological Psychology
  • Neurology
  • Psychiatry and Mental health
  • Biological Psychiatry
  • Behavioral Neuroscience

Cite this

Speed-dependent modulation of muscle activity based on muscle synergies during treadmill walking. / Kibushi, Benio; Hagio, Shota; Moritani, Toshio; Kouzaki, Motoki.

In: Frontiers in Human Neuroscience, Vol. 12, 4, 24.01.2018.

Research output: Contribution to journalArticle

@article{dc4a70a9793d4b05a8e6b30a437160cc,
title = "Speed-dependent modulation of muscle activity based on muscle synergies during treadmill walking",
abstract = "The regulation of walking speed is easily achieved. However, the central nervous system (CNS) must coordinate numerous muscles in order to achieve a smooth and continuous control of walking speed. To control walking speed appropriately, the CNS may need to utilize a simplified system for the control of numerous muscles. Previous studies have revealed that the CNS may control walking via muscle synergies that simplify the control of muscles by modularly organizing several muscles. We hypothesized that the CNS controls the walking speed by flexibly modulating activation of muscle synergies within one gait cycle. Then, we investigated how the activation of muscle synergies depend on walking speeds using the center of activity (CoA) that indicates the center of the distribution of activation timing within one gait cycle. Ten healthy men walked on a treadmill at 14 different walking speeds. We measured the surface electromyograms (EMGs) and kinematic data. Muscle synergies were extracted using non-negative matrix factorization. Then, we calculated the CoA of each muscle synergy. We observed that the CoA of each specific synergy would shift as the walking speed changed. The CoA that was mainly activated during the heel contact phase (C1) and the activation that contributed to the double support phase (C3) shifted to the earlier phase as the walking speed increased, whereas the CoA that produced swing initiation motion (C4) and the activation that related to the late-swing phase (C5) shifted to the later phase. This shifting of the CoAindicates that the CNScontrols intensive activation of muscle synergies during the regulation of walking speed. In addition, shifting the CoA might be associated with changes in kinematics or kinetics depending on the walking speed. We concluded that the CNSflexibly controls the activation of muscle synergies in regulation of walking speed.",
keywords = "Center of activity, Central nervous system, Electromyograms, Joint acceleration, Motor control, Non-negative matrix factorization",
author = "Benio Kibushi and Shota Hagio and Toshio Moritani and Motoki Kouzaki",
year = "2018",
month = "1",
day = "24",
doi = "10.3389/fnhum.2018.00004",
language = "English",
volume = "12",
journal = "Frontiers in Human Neuroscience",
issn = "1662-5161",
publisher = "Frontiers Research Foundation",

}

TY - JOUR

T1 - Speed-dependent modulation of muscle activity based on muscle synergies during treadmill walking

AU - Kibushi, Benio

AU - Hagio, Shota

AU - Moritani, Toshio

AU - Kouzaki, Motoki

PY - 2018/1/24

Y1 - 2018/1/24

N2 - The regulation of walking speed is easily achieved. However, the central nervous system (CNS) must coordinate numerous muscles in order to achieve a smooth and continuous control of walking speed. To control walking speed appropriately, the CNS may need to utilize a simplified system for the control of numerous muscles. Previous studies have revealed that the CNS may control walking via muscle synergies that simplify the control of muscles by modularly organizing several muscles. We hypothesized that the CNS controls the walking speed by flexibly modulating activation of muscle synergies within one gait cycle. Then, we investigated how the activation of muscle synergies depend on walking speeds using the center of activity (CoA) that indicates the center of the distribution of activation timing within one gait cycle. Ten healthy men walked on a treadmill at 14 different walking speeds. We measured the surface electromyograms (EMGs) and kinematic data. Muscle synergies were extracted using non-negative matrix factorization. Then, we calculated the CoA of each muscle synergy. We observed that the CoA of each specific synergy would shift as the walking speed changed. The CoA that was mainly activated during the heel contact phase (C1) and the activation that contributed to the double support phase (C3) shifted to the earlier phase as the walking speed increased, whereas the CoA that produced swing initiation motion (C4) and the activation that related to the late-swing phase (C5) shifted to the later phase. This shifting of the CoAindicates that the CNScontrols intensive activation of muscle synergies during the regulation of walking speed. In addition, shifting the CoA might be associated with changes in kinematics or kinetics depending on the walking speed. We concluded that the CNSflexibly controls the activation of muscle synergies in regulation of walking speed.

AB - The regulation of walking speed is easily achieved. However, the central nervous system (CNS) must coordinate numerous muscles in order to achieve a smooth and continuous control of walking speed. To control walking speed appropriately, the CNS may need to utilize a simplified system for the control of numerous muscles. Previous studies have revealed that the CNS may control walking via muscle synergies that simplify the control of muscles by modularly organizing several muscles. We hypothesized that the CNS controls the walking speed by flexibly modulating activation of muscle synergies within one gait cycle. Then, we investigated how the activation of muscle synergies depend on walking speeds using the center of activity (CoA) that indicates the center of the distribution of activation timing within one gait cycle. Ten healthy men walked on a treadmill at 14 different walking speeds. We measured the surface electromyograms (EMGs) and kinematic data. Muscle synergies were extracted using non-negative matrix factorization. Then, we calculated the CoA of each muscle synergy. We observed that the CoA of each specific synergy would shift as the walking speed changed. The CoA that was mainly activated during the heel contact phase (C1) and the activation that contributed to the double support phase (C3) shifted to the earlier phase as the walking speed increased, whereas the CoA that produced swing initiation motion (C4) and the activation that related to the late-swing phase (C5) shifted to the later phase. This shifting of the CoAindicates that the CNScontrols intensive activation of muscle synergies during the regulation of walking speed. In addition, shifting the CoA might be associated with changes in kinematics or kinetics depending on the walking speed. We concluded that the CNSflexibly controls the activation of muscle synergies in regulation of walking speed.

KW - Center of activity

KW - Central nervous system

KW - Electromyograms

KW - Joint acceleration

KW - Motor control

KW - Non-negative matrix factorization

UR - http://www.scopus.com/inward/record.url?scp=85041462857&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85041462857&partnerID=8YFLogxK

U2 - 10.3389/fnhum.2018.00004

DO - 10.3389/fnhum.2018.00004

M3 - Article

VL - 12

JO - Frontiers in Human Neuroscience

JF - Frontiers in Human Neuroscience

SN - 1662-5161

M1 - 4

ER -