Estimation of centre of gravity movements in sitting posture: application to trunk backward tilt.
Summary of "Estimation of centre of gravity movements in sitting posture: application to trunk backward tilt."
The aim of this study was to highlight, in sitting posture, the value of distinguishing between the movements of the vertical projection of the centre of gravity (CG(v)) and its difference from the centre of pressure (CP-CG(v)). A protocol for healthy, young, trained adults, consisting in tilting their trunk backward or keeping it vertical was used. A frequency analysis shows that statistically significant effects were only seen on CP-CG(v) movements: the RMS increased by 37% (p=0.004), while the MPF decreased by 5% (p=0.016), suggesting an increased muscular activity in these tilting postures. In contrast, no statistically significant effects on CP and CG(v) were reported. These data highlight the advantage, in sitting posture, of splitting overall CP displacements into basic components (i.e. CG(v) and CP-CG(v)), each of them having a biomechanical significance.
Affiliation
Université de Savoie, Domaine scientifique de Savoie-Technolac, Laboratoire de Physiologie de l'Exercice-EA4338, 73376 Le-Bourget-du-Lac, France.
Journal Details
This article was published in the following journal.
Name: Journal of biomechanics
ISSN: 1873-2380
Pages: 1771-5
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21549381
- DOI: http://dx.doi.org/10.1016/j.jbiomech.2011.04.008
Medical and Biotech [MESH] Definitions
Postural Balance
A POSTURE in which an ideal body mass distribution is achieved. Postural balance provides the body carriage stability and conditions for normal functions in stationary position or in movement, such as sitting, standing, or walking.
Freezing Reaction, Cataleptic
An induced response to threatening stimuli characterized by the cessation of body movements, except for those that are involved with BREATHING, and the maintenance of an immobile POSTURE.
Gravity Sensing
Process whereby a cell, bodily structure, or organism (animal or plant) receives or detects a gravity stimulus. Gravity sensing plays an important role in the directional growth and development of an organism (GRAVITROPISM).
Dyskinesia, Drug-induced
Abnormal movements, including HYPERKINESIS; HYPOKINESIA; TREMOR; and DYSTONIA, associated with the use of certain medications or drugs. Muscles of the face, trunk, neck, and extremities are most commonly affected. Tardive dyskinesia refers to abnormal hyperkinetic movements of the muscles of the face, tongue, and neck associated with the use of neuroleptic agents (see ANTIPSYCHOTIC AGENTS). (Adams et al., Principles of Neurology, 6th ed, p1199)
Dystonia
An attitude or posture due to the co-contraction of agonists and antagonist muscles in one region of the body. It most often affects the large axial muscles of the trunk and limb girdles. Conditions which feature persistent or recurrent episodes of dystonia as a primary manifestation of disease are referred to as DYSTONIC DISORDERS. (Adams et al., Principles of Neurology, 6th ed, p77)
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