Modular control of muscle coordination patterns during various stride time and stride length combinations.
Central nervous system
Electromyograms
Kinematics
Motor control
Walking
Journal
Gait & posture
ISSN: 1879-2219
Titre abrégé: Gait Posture
Pays: England
ID NLM: 9416830
Informations de publication
Date de publication:
05 2022
05 2022
Historique:
received:
03
09
2020
revised:
09
03
2021
accepted:
04
04
2021
pubmed:
22
5
2021
medline:
11
5
2022
entrez:
21
5
2021
Statut:
ppublish
Résumé
Modular organization in muscular control is generally specified as synergistic muscle groups that are hierarchically organized. There are conflicting perspectives regarding modular organization for regulation of walking speeds, with regard to whether modular organization is relatively consistent across walking speeds. This conflict might arise from different stride time (time for one stride) and stride length combinations for achieving the same walking speed. Does the regulation of the modular organization depend on stride time and stride length (stride time-length) combinations? Ten healthy men walked at a moderate speed (nondimensional speed = 0.4) on a treadmill at five different stride time-length combinations (very short, short, preferred, long, and very long). Surface electromyograms from 16 muscles in the trunk and lower limb were recorded. The modular organization was modeled as muscle synergies, which represent groups of synchronously activated muscles. Muscle synergies were extracted using a decomposition technique. The number of synergies and their activation durations were analyzed. The number of synergies was consistent in the preferred and quasi-preferred condition (median: 4.5 [short], 4.5 [preferred], 5 [long]), while it varied in the extreme condition (median: 4 [very short] and 6 [very long]; 0.02 ≤ p ≤ 0.09). Gait parameters (stride time, stride length, stance time, swing time, and double stance time) were significantly different for preferred and quasi-preferred conditions (p < 0.03). Our results provide additional insights on the flexibility of modular control during walking, namely that the number of synergies or activations are fine-tuned even within one walking speed. Our finding implies that a variety of walking patterns can be achieved by consistent synergies except for extreme walking patterns.
Sections du résumé
BACKGROUND
Modular organization in muscular control is generally specified as synergistic muscle groups that are hierarchically organized. There are conflicting perspectives regarding modular organization for regulation of walking speeds, with regard to whether modular organization is relatively consistent across walking speeds. This conflict might arise from different stride time (time for one stride) and stride length combinations for achieving the same walking speed.
RESEARCH QUESTION
Does the regulation of the modular organization depend on stride time and stride length (stride time-length) combinations?
METHODS
Ten healthy men walked at a moderate speed (nondimensional speed = 0.4) on a treadmill at five different stride time-length combinations (very short, short, preferred, long, and very long). Surface electromyograms from 16 muscles in the trunk and lower limb were recorded. The modular organization was modeled as muscle synergies, which represent groups of synchronously activated muscles. Muscle synergies were extracted using a decomposition technique. The number of synergies and their activation durations were analyzed.
RESULTS
The number of synergies was consistent in the preferred and quasi-preferred condition (median: 4.5 [short], 4.5 [preferred], 5 [long]), while it varied in the extreme condition (median: 4 [very short] and 6 [very long]; 0.02 ≤ p ≤ 0.09). Gait parameters (stride time, stride length, stance time, swing time, and double stance time) were significantly different for preferred and quasi-preferred conditions (p < 0.03).
SIGNIFICANCE
Our results provide additional insights on the flexibility of modular control during walking, namely that the number of synergies or activations are fine-tuned even within one walking speed. Our finding implies that a variety of walking patterns can be achieved by consistent synergies except for extreme walking patterns.
Identifiants
pubmed: 34016506
pii: S0966-6362(21)00128-4
doi: 10.1016/j.gaitpost.2021.04.006
pii:
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
230-235Informations de copyright
Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.