title: Application of cross time-frequency analysis to postural sway behavior: the effects of aging and visual systems.
abstract: In this paper, the effects of visual feedback and aging on postural sway systems and signals are investigated by analyzing the transient phase difference between "input" and "output" which correspond to center of pressure (COP) and center of mass (COM), respectively. In order to analyze the transient phase difference characteristics of COP and COM, a relatively new cross time-frequency analysis technique that provides time- and frequency-localized phase difference information is utilized. The feedback control process in the postural sway is interpreted in terms of a feedback compensator which is characterized in terms of a phase difference. Using the experimental results of the transient phase difference obtained from the cross time-frequency distribution, it is demonstrated that the postural control of young persons are more stable and rely more on visual sensory feedback to stabilize postural control compared to that of the elderly persons.
authors.affiliation: Department of Electrical Engineering, The University of South Carolina, Columbia, SC 29208, USA. shinjune@engr.sc.edu
authors.forename: Yong-June
authors.initials: YJ
authors.lastname: Shin
authors.forename: Denise
authors.initials: D
authors.lastname: Gobert
authors.forename: Seung-Hoon
authors.initials: SH
authors.lastname: Sung
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Powers
authors.forename: Jin Bae
authors.initials: JB
authors.lastname: Park
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000465:Algorithms; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005246:Feedback / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D009043:Motor Activity / Q000502:physiology; D009068:Movement / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012044:Regression Analysis; D013223:Statistics as Topic; D014785:Vision, Ocular / Q000502:physiology*