Background. Studies indicate that the strategy for postural control may be affected by psychological factors, and that young adults respond to perceived threat to stability by increasing their ankle stiffness. The objective of this study was to compare the postural control strategy adopted by young and old adults when faced with postural threat induced by manipulating surface height. Methods. Sixty elderly (mean age 77.5 ± 4.4 years) and 20 young volunteers (mean age 21.5 ± 3.7 years) participated in the study. Movement of the center of pressure (COP) was recorded for 60 seconds with a portable force-plate, as participants stood with eyes open and closed, both at ground level and 85 cm above ground level. Analysis of variance and Tukey-Kramer tests were conducted to determine the effects of age, postural threat, and vision on mean power frequency (MPF), on amplitude variability both in the anterior-posterior (AP) and medio-lateral (ML) directions, and on mean COP sway velocity, with the significance level set at p = .05. Results. Postural threat did not affect COP measures for the young adults, whereas it induced greater changes in MPF in the AP and ML directions in the elderly participants. A similar trend was observed in the elderly group for amplitude variability in the ML direction and for mean COP sway velocity. Conclusions. In comparison with young adults, elderly adults tend to have an exaggerated postural response to conditions that are perceived as threatening to stability. This response involves primarily increases in MPF, with limited compensatory decreases in amplitude variability observed only in the ML direction.
|Number of pages
|Journals of Gerontology - Series A Biological Sciences and Medical Sciences
|Published - May 2006
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS This research was supported by research project grants MH43261 and MH47346 from the National Institute of Mental Health (GSZ) and EY11733 from the National Eye Institute (NSW). GSZ was the recipient of Independent Scientist Award MH00540 from the National Institute of Mental Health.
ASJC Scopus subject areas
- Geriatrics and Gerontology