Vibratory noise to the fingertip enhances balance improvement associated with light touch


Autoria(s): Magalhães, Fernando Henrique; Kohn, Andre Fabio
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

18/10/2012

18/10/2012

2011

Resumo

Light touch of a fingertip on an external stable surface greatly improves the postural stability of standing subjects. The hypothesis of the present work was that a vibrating surface could increase the effectiveness of fingertip signaling to the central nervous system (e.g., by a stochastic resonance mechanism) and hence improve postural stability beyond that achieved by light touch. Subjects stood quietly over a force plate while touching with their right index fingertip a surface that could be either quiescent or randomly vibrated at two low-level noise intensities. The vibratory noise of the contact surface caused a significant decrease in postural sway, as assessed by center of pressure measures in both time and frequency domains. Complementary experiments were designed to test whether postural control improvements were associated with a stochastic resonance mechanism or whether attentional mechanisms could be contributing. A full curve relating body sway parameters and different levels of vibratory noise resulted in a U-like function, suggesting that the improvement in sway relied on a stochastic resonance mechanism. Additionally, no decrease in postural sway was observed when the vibrating contact surface was attached to the subject`s body, suggesting that no attentional mechanisms were involved. These results indicate that sensory cues obtained from the fingertip need not necessarily be associated with static contact surfaces to cause improvement in postural stability. A low-level noisy vibration applied to the contact surface could lead to a better performance of the postural control system.

CNPq

FAPESP[2007/03608-9]

Identificador

EXPERIMENTAL BRAIN RESEARCH, v.209, n.1, p.139-151, 2011

0014-4819

http://producao.usp.br/handle/BDPI/18673

10.1007/s00221-010-2529-3

http://dx.doi.org/10.1007/s00221-010-2529-3

Idioma(s)

eng

Publicador

SPRINGER

Relação

Experimental Brain Research

Direitos

restrictedAccess

Copyright SPRINGER

Palavras-Chave #Sway #Stochastic resonance #Vibration #Postural control #Somatosensation #Posture stabilization #HUMAN POSTURAL CONTROL #STOCHASTIC RESONANCE #OLDER-ADULTS #INDEX FINGER #CONTACT #BODY #STABILIZATION #INFORMATION #SYSTEM #SWAY #Neurosciences
Tipo

article

original article

publishedVersion