Author: Tassani S1, Font-Llagunes JM2, González Ballester MÁ3, Noailly J4
1Universitat Pompeu Fabra, BCN MedTech, Barcelona, Spain. Electronic address: firstname.lastname@example.org.
2Universitat Politècnica de Catalunya, Biomechanical Engineering Lab, Department of Mechanical Engineering and Biomedical Engineering Research Centre, Barcelona, Spain; Institut de Recerca Sant Joan de Déu, Biomedical Engineering, Esplugues de Llobregat, Spain.
3Universitat Pompeu Fabra, BCN MedTech, Barcelona, Spain; ICREA, Barcelona, Spain.
4Universitat Pompeu Fabra, BCN MedTech, Barcelona, Spain.
Conference/Journal: Gait Posture.
Date published: 2019 Feb
Other: Volume ID: 68 , Pages: 220-226 , Special Notes: doi: 10.1016/j.gaitpost.2018.11.034. Epub 2018 Nov 28. , Word Count: 311
BACKGROUND: Muscular co-contraction is a strategy commonly used by elders with the aim to increase stability. However, co-contraction leads to stiffness which in turns reduces stability. Some literature seems to suggest an opposite approach and to point out relaxation as a way to improve stability. Teaching relaxation is therefore becoming the aim of many studies letting unclear whether tension or relaxation are the most effective muscular strategy to improve stability. Relaxation is a misleading concept in our society. It is often confused with rest, while it should be addressed during stressing tasks, where it should aim to reduce energetic costs and increase stability. The inability to relax can be related to sub-optimal neuro-motor control, which can lead to increased stresses.
RESEARCH QUESTION: The objective of the study is to investigate the effect of voluntary muscle contraction and relaxation over the stability of human standing posture, answering two specific research questions: (1) Does the muscular tension have an impact on stability of standing posture? (2) Could this impact be estimated by using a minimally invasive procedure?
METHODS: By using a force plate, we analysed the displacement of the center of pressure of 30 volunteers during state of tension and relaxation in comparison with a control state, and with open and closed eyes.
RESULTS: We found that tension significantly reduced the stability of subjects (15 out of 16 parameters, p < 0.003).
SIGNIFICANCE: Our results show that daily situations of stress can lead to decreased stability. Such a loss might actually increase the risk of chronic joint overload or fall. Finally, breathing has direct effect over the management of pain and stress, and the results reported here point out the need to explicitly explore the troubling fact that a large portion of population might not be able to properly breath.
Copyright © 2018 Elsevier B.V. All rights reserved.
KEYWORDS: Muscular relaxation; Muscular tension; Postural analysis; Stability
PMID: 30517907 DOI: 10.1016/j.gaitpost.2018.11.034