Changes in postural sway and its fractions in conditions of postural instability

Luis Mochizuki, Marcos Duarte, Alberto Carlos Amadio, Vladimir M. Zatsiorsky, Mark Latash

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

We investigated changes in postural sway and its fractions associated with manipulations of the dimensions of the support area. Nine healthy adults stood as quietly as possible, with their eyes open, on a force plate as well as on 5 boards with reduced support area. The center of pressure (COP) trajectory was computed and decomposed into rambling (Rm) and trembling (Tr) trajectories. Sway components were quantified using RMS (root mean square) value, average velocity, and sway area. During standing on the force plate, the RMS was larger for the anterior-posterior (AP) sway components than for the mediolateral (ML) components. During standing on boards with reduced support area, sway increased in both directions. The increase was more pronounced when standing on boards with a smaller support area. Changes in the larger dimension of the support area also affected sway, but not as much as changes in the smaller dimension. ML instability had larger effects on indices of sway compared to AP instability. The average velocity of Rm was larger while the average velocity of Tr was smaller in the AP direction vs. the ML direction. The findings can be interpreted within the hypothesis of an active search function of postural sway. During standing on boards with reduced support area, increased sway may by itself lead to loss of balance. The findings also corroborate the hypothesis of Duarte and Zatsiorsky that Rm and Tr reveal different postural control mechanisms.

Original languageEnglish (US)
Pages (from-to)51-60
Number of pages10
JournalJournal of applied biomechanics
Volume22
Issue number1
DOIs
StatePublished - Jan 1 2006

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All Science Journal Classification (ASJC) codes

  • Biophysics
  • Orthopedics and Sports Medicine
  • Rehabilitation

Cite this

Mochizuki, Luis ; Duarte, Marcos ; Amadio, Alberto Carlos ; Zatsiorsky, Vladimir M. ; Latash, Mark. / Changes in postural sway and its fractions in conditions of postural instability. In: Journal of applied biomechanics. 2006 ; Vol. 22, No. 1. pp. 51-60.
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Changes in postural sway and its fractions in conditions of postural instability. / Mochizuki, Luis; Duarte, Marcos; Amadio, Alberto Carlos; Zatsiorsky, Vladimir M.; Latash, Mark.

In: Journal of applied biomechanics, Vol. 22, No. 1, 01.01.2006, p. 51-60.

Research output: Contribution to journalArticle

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