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Postural Sway Complexity in Healthy Older Adults and Individuals with Asthma

Kuznetsov, Nikita Aleksandrovich
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112671

Abstract Details

2013, PhD, University of Cincinnati, Arts and Sciences: Psychology.
The goal of the dissertation was to examine the loss of complexity hypothesis in context of postural control of healthy community-dwelling older adults (over 65) and younger adults with asthma (under 30). The loss of complexity provides a dynamical systems framework for understanding the relation between adaptability and complexity of a physiological (or behavioral) system and the dynamics of the resulting output from this system. It predicts that with the simplification of the system due to aging and disease (e.g., loss of functional degrees of freedom or coupling between them), the outputs measured from the system deviate from healthy irregular dynamics (characterized by 1/f-like fluctuations or intermediate entropy values) toward more regular or more irregular dynamics. I examined these ideas using the center of pressure (COP) as a variable to quantify postural control complexity in four experiments that emphasized the stabilizing capacity of the postural control system. In the first three studies, participants were required to maintain their COP on a stationary target while seeing visual feedback about their COP in real time. Two studies on aging demonstrated that older adults were not always more regular than younger adults as quantified by sample entropy. Older adults in Experiment 1 typically had more regular and more variable COP fluctuations in the feedback condition, but did not differ in COP regularity from younger adults in the no-feedback condition. Older adults with higher Berg balance scale scores also had more irregular ML COP dynamics only in the feedback condition. In the second aging experiment there were no age differences in COP regularity either when standing with equally distributed pressure or leaning more on left or right foot. The two studies on asthma also demonstrated a similar task-dependence of COP regularity differences. People with asthma were more regular in their AP COP than the controls in both feedback and no-feedback conditions of Experiment 3. These differences were accounted for by the group differences in static posture and anxiety sensitivity. However, Experiment 4 revealed that postural control differences between the asthmatics and controls were more pronounced when standing on a narrow base of support as opposed to full support (which were not accounted by anxiety sensitivity differences). In all of the experiments, I also calculated the degree of mathematical coupling between breathing and COP to quantify the level of integration between the respiratory and postural control synergies. None of the studies showed any systematic group differences on this metric, indicating that the level of integration between the respiratory and postural systems was not altered. Overall, the results suggest that the loss of complexity hypothesis requires consideration task constraints in addition to the typically emphasized organismic constraints.
Michael Riley, Ph.D. (Committee Chair)
Michael Richardson, Ph.D. (Committee Member)
Kevin Shockley, Ph.D. (Committee Member)
172 p.
Experiments
postural control; complexity; aging; asthma

Recommended Citations

Citations

  • Kuznetsov, N. A. (2013). Postural Sway Complexity in Healthy Older Adults and Individuals with Asthma [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112671

    APA Style (7th edition)

  • Kuznetsov, Nikita. Postural Sway Complexity in Healthy Older Adults and Individuals with Asthma. 2013. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112671.

    MLA Style (8th edition)

  • Kuznetsov, Nikita. "Postural Sway Complexity in Healthy Older Adults and Individuals with Asthma." Doctoral dissertation, University of Cincinnati, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112671

    Chicago Manual of Style (17th edition)

ucin1378112671
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© 2013, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.