title: Beyond deficit or compensation: new insights on postural control after long-term total visual loss.
abstract: Loss of vision is well known to affect postural control in blind subjects. This effect has classically been framed in terms of deficit or compensation depending on whether body sway increases or decreases in comparison with that of sighted subjects with the eyes open. However, studies have shown that postural responses can be modulated by the context and that changes in postural sway may not necessarily mean a worsened or improved postural control. The goal of our study was to test whether balance is affected by the context in blind subjects. Additional to the quantification of center of pressure (COP) displacement, measurements of body motion (COG) and the correspondent net neuromuscular response (COP-COG) were evaluated in anterior-posterior and medial-lateral directions. Thirty-eight completely blind and thirty-two sighted subjects participated of this study. The volunteers were asked to stand barefoot on a force platform for 60 s in two different conditions: feet apart and feet together. Sighted participants performed the tests with both the eyes open and eyes closed. Results showed that the COP-COG displacements in the blind group were greater than those of the sighted group with eyes open in almost all conditions tested, but not in eyes closed condition. However, the COP and COG results confirmed that the postural responses were context dependent. Together these results suggest that total visual loss does not just lead to a balance deficit or compensation, but to a specific postural signature that might imply in enhancing COP, COG and/or COP-COG in specific postural conditions.
authors: Laboratório de Neurobiologia II, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro, 21949-900, Brazil. maite@biof.ufrj.br.
authors: Maitê M
authors: MM
authors: Russo
authors: Programa de Pós-Graduação em Ciências da Reabilitação, Centro Universitário Augusto Mota (UNISUAM), Rio de Janeiro, Brazil.
authors: Thiago
authors: T
authors: Lemos
authors: Núcleo de Estudos do Movimento Humano (NEMoH), Escola de Educação Física e Desportos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Luís A
authors: LA
authors: Imbiriba
authors: Núcleo de Estudos do Movimento Humano (NEMoH), Escola de Educação Física e Desportos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Nathalia L
authors: NL
authors: Ribeiro
authors: Laboratório de Neurobiologia II, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro, 21949-900, Brazil.|Laboratório de Neurociencias e Reabilitação, Instituto de Neurologia Deolindo Couto, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Claudia D
authors: CD
authors: Vargas
mesh_terms: D000293:Adolescent; D000328:Adult; D001766:Blindness / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D009038:Motion; D009949:Orientation / Q000502:physiology; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011312:Pressure; D012678:Sensation Disorders / Q000209:etiology*; D018709:Statistics, Nonparametric; D055815:Young Adult
keywords: Balance control; Blindness; Body sway; Visual loss