Light touch modulates balance recovery following perturbation: from fast response to stance restabilization

Autor(es)

Martinelli, Alessandra Rezende ^[1] ; Coelho, Daniel Boari ^[1] ; Magalhaes, Fernando Henrique ^[2] ; Kohn, Andre Fabio ^[2] ; Teixeira, Luis Augusto ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Human Motor Syst Lab, Sch Phys Educ & Sport, BR-05508030 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Biomed Engn Lab, Escola Politecn, BR-05586060 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Experimental Brain Research; v. 233, n. 5, p. 1399-1408, MAY 2015.
• Citações Web of Science: 7

Resumo

Light fingertip touch of a static bar generates extra somatosensory information used by the postural control system to reduce body sway. While the effect of light touch has been studied in quiet stance, less attention has been given to its potential benefit for reactive postural responses. In the present study, we tested the effect of light fingertip touch of a stable surface on recovery of postural stability from a mechanical perturbation. Participants stood upright on a force plate touching a static rigid bar while being pulled backward by a load. Unpredictable release of the load induced fast anterior body sway, requiring a reactive response to recover balance. Effect of light touch on postural responses was assessed as a function of vision and malleability of the support surface, analyzing different epochs ranging from the pre-perturbation period to recovery of a relatively stable quiet stance. Results showed that light touch induced lower magnitude of muscular activation in all epochs. Center of pressure (CoP) displacement/sway was affected by interaction of light touch with manipulation of the other sensory information. For the periods associated with quiet stance, light touch led to decreased CoP sway in the malleable surface in the pre-perturbation epoch, and in the condition combining no vision and malleable surface in the balance restabilization and follow-up quiet stance epochs. For the fast reactive response epoch, light touch induced smaller amplitude of CoP displacement across conditions, and lower CoP maximum velocity in the condition combining no vision and rigid surface. These results showed that light touch modulates postural responses in all epochs associated with an unanticipated mechanical perturbation, with a more noticeable effect in conditions manipulating sensory information relevant for balance control. (AU)

• Processo FAPESP: 13/00639-1 - Respostas posturais a perturbações extrínsecas e restrição sensorial após acidente vascular encefálico: efeito de informação tátil adicional
• Beneficiário: Luis Augusto Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
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• Beneficiário: Fernando Henrique Magalhães
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 11/18173-3 - Recuperação do equilíbrio corporal em indivíduos pós-acidente vascular encefálico: reabilitação e ganho de estabilidade por toque em superfície vibratória
• Beneficiário: Alessandra Rezende Martinelli Conterato
• Modalidade de apoio: Bolsas no Brasil - Doutorado