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Date of Award


Degree Type

Thesis (On-Campus Access Only)

Degree Name

Master of Physical Therapy (MPT)

First Advisor

Davia Banaitis, PhD, PT

Second Advisor

Patricia Tangeman, MEd, PT


The purpose of this study was to examine the changes in postural sway in static sitting and static standing as one ages. Past studies have indicated that static standing postural sway does increase, particularly after 70 years of age. The sample of this study had six age groups from ages 21 to 81 years old with a total of 68 subjects. Postural sway area was measured with the subject sitting upright for 60 seconds on a chair force plate and then standing on a standing force plate for 60 seconds. The results showed a minimal relationship (r = 0.157) between age and sitting average sway, and a minimal relationship (r - 0.243) between age and standing average sway. There was also a minimal relationship (r = 0.153) between sitting average sway and standing average sway. Analysis of variance showed an insignificant difference within age groups and between age groups of sitting average sway F(6, 1.029), p < 0.416, and standing average sway F(6, 1.063), p < 0.394. Discrepancies of the study's results with the literature may be due to differences in apparatus used and research design. Possible sources of error are the small number of subjects in the 70 and older age group, inconsistencies of sitting and standing postures, and controlling extraneous variables in the questionnaire. The results imply that sitting and standing balance have different mechanisms and processes in maintaining these two postures. The influence of aging on sitting and standing postural sway is still inconclusive and ambiguous. It may be that the variability of the health status of older subjects may explain the inconsistencies of this study.


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