Mahmood, I, Martinez-Hernandez, U and Dehghani-Sanij, AA (2020) A model identification approach to quantify impact of whole-body vertical vibrations on limb compliant dynamics and walking stability. Medical Engineering & Physics, 80. pp. 8-17. ISSN 1350-4533
Abstract
Extensive research is ongoing in the field of orthoses/exoskeleton design for efficient lower limbs assistance. However, despite wearable devices reported to improve lower limb mobility, their structural impacts on whole-body vertical dynamics have not been investigated. This study introduced a model identification approach and frequency domain analysis to quantify the impacts of orthosis-generated vibrations on limb stability and contractile dynamics. Experiments were recorded in the motion capture lab using 11 unimpaired subjects by wearing an adjustable ankle–foot orthosis (AFO). The lower limb musculoskeletal structure was identified as spring-mass (SM) and spring-mass-damper (SMD) based compliant models using the whole-body centre-of-mass acceleration data. Furthermore, Nyquist and Bode methods were implemented to quantify stabilities resulting from vertical impacts. Our results illustrated a significant decrease (p < 0.05) in lower limb contractile properties by wearing AFO compared with a normal walk. Also, stability margins quantified by wearing AFO illustrated a significant variance in terms of gain-margins (p < 0.05) for both loading and unloading phases whereas phase-margins decreased (p < 0.05) only for the respective unloading phases. The methods introduced here provide evidence that wearable orthoses significantly affect lower limb vertical dynamics and should be considered when evaluating orthosis/prosthesis/exoskeleton effectiveness.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 IPEM. Published by Elsevier Ltd. All rights reserved. This is an author produced version of an article published in Medical Engineering & Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Ankle–foot orthosis; Limb contractile properties; Dynamic stability; Gait; Vertical impacts; Loading and unloading phases; Wearable devices |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Engineering Systems and Design (iESD) (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Apr 2021 15:52 |
Last Modified: | 21 Jun 2021 10:28 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.medengphy.2020.04.005 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:173141 |
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