The strength of Long-range correlations of postural sway is greater in older fallers than non-fallers
Advisor Information
Mukul Mukherjee
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
7-3-2014 1:00 PM
End Date
7-3-2014 4:00 PM
Abstract
Falling is a major concern and results from an inability to maintain postural control during daily activities. The ability to maintain the center of pressure (COP) within the base of support during standing is a reflection of postural control. Mediolateral COP has been used to predict falls.1 However, the temporal structure of mediolateral COP in older fallers compared to non-fallers remains largely unknown. The temporal structure of biological signals has been used to characterize the dynamics of human movement.2 It has been suggested that an optimal temporal structure of human movement variability exists that permits the maintenance of a desired movement pattern while still allowing the system the adaptability needed to interact optimally with a dynamic environment. This research used Detrended Fluctuation Analysis (DFA) to measure the long-range correlations in standing posture; DFA α-values provide a measure of the temporal correlations. Three groups were analyzed; young non-fallers (n = 9), older non-fallers (n = 10), and older fallers (n = 5). Participants stood on a force platform while center of pressure was recorded in three conditions, normal standing, absent vision, and faulty vision. The results demonstrated stronger long-range correlations in older fallers (α = 1.29) when compared to the older non-fallers (α = 1.06; P = .009) and young non-fallers (α = 0.95; P < .001). Stronger long-range correlations demonstrate a more rigid and constrained mediolateral postural sway. This indicates a lowering of the flexibility and adaptability necessary for older fallers to interact with a dynamic environment without falling.
The strength of Long-range correlations of postural sway is greater in older fallers than non-fallers
Dr. C.C. and Mabel L. Criss Library
Falling is a major concern and results from an inability to maintain postural control during daily activities. The ability to maintain the center of pressure (COP) within the base of support during standing is a reflection of postural control. Mediolateral COP has been used to predict falls.1 However, the temporal structure of mediolateral COP in older fallers compared to non-fallers remains largely unknown. The temporal structure of biological signals has been used to characterize the dynamics of human movement.2 It has been suggested that an optimal temporal structure of human movement variability exists that permits the maintenance of a desired movement pattern while still allowing the system the adaptability needed to interact optimally with a dynamic environment. This research used Detrended Fluctuation Analysis (DFA) to measure the long-range correlations in standing posture; DFA α-values provide a measure of the temporal correlations. Three groups were analyzed; young non-fallers (n = 9), older non-fallers (n = 10), and older fallers (n = 5). Participants stood on a force platform while center of pressure was recorded in three conditions, normal standing, absent vision, and faulty vision. The results demonstrated stronger long-range correlations in older fallers (α = 1.29) when compared to the older non-fallers (α = 1.06; P = .009) and young non-fallers (α = 0.95; P < .001). Stronger long-range correlations demonstrate a more rigid and constrained mediolateral postural sway. This indicates a lowering of the flexibility and adaptability necessary for older fallers to interact with a dynamic environment without falling.