Dynamics of Modular Neuromotor Control of Walking and Running during Single and Dual Task Conditions. (15th June 2021)

• Record Type: Journal Article
• Authors: Walsh, Gregory S.
• Is Part Of: Neuroscience. Volume 465(2021)
• Page Start: 1
• Page End: 10
• Publication Date: 2021-06-15
• Subjects: gait -- electromyography -- muscle synergy -- complexity -- local dynamic stability; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2021.04.004
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: Muscle synergy stability was greater in dual task conditions than single task. Increasing locomotion speed decreased muscle synergy stability and complexity. Centre of mass motion became less stable and more complex with increasing speed. Vertical centre of mass motion was more complex and less stable in dual tasking. Neuromotor (synergy) stability likely moderates changes in gait local stability. Abstract: The aim of the study was to determine the stability and complexity of muscle synergies to provide insight to the neural control of gait stability in walking and running and when performing a concurrent cognitive dual task. Eighteen healthy young adults performed walking and running at preferred speeds and 120% of preferred speeds in single and dual task conditions. Muscle synergies were determined from the activity of 9 trunk and leg muscles and centre of mass (COM) motion was recorded with an inertial measurement unit. Local dynamic stability, complexity and width of synergies, and stability and complexity of COM motion were determined, in addition to the cross sample entropy to determine the coupling between COM motion and muscle synergies. Increasing locomotion speed increased complexity and decreased stability of COM motion with a concurrent decrease in synergy complexity and stability but with no change in synergy width. The coupling of COM motion and muscle synergies also increased with increasing speed. Vertical COM motion was more complex and less stable but with no change in anterior-posterior or medio-lateral directions in dual task locomotion. Muscle synergies were also more stable in dual task conditions. These findings indicate that changes in neuromotor dynamics may underpin reported changes in COM local stability during gait as the neural commands responsible for generating the movement are altered in response to increasing task demands. Increased cognitive demands lead to more stable neuromotor commands possibly to maintain local stability of COM motion in the anterior-posterior and medio-lateral directions.