title: The Stochastic Component of the Postural Sway Variability is Higher in Children with Balance Impairments.
abstract: Children with balance impairments have an increased amount of variability in the sway of the center of pressure (COP) during standing. Limited efforts have been made to quantify the nature of the variability. This exploratory investigation examined the deterministic and stochastic features that comprise the time-dependent postural sway variability during standing. We measured the COP in standing of a heterogeneous group of children with balance impairments and an age-matched cohort of typically developing children, both with and without vision. The standard deviation of the COP was used to quantify the amount of variability present in the postural sway. A Langevin equation methodology was additionally employed to reconstruct the deterministic and stochastic features that comprised the postural sway variability. Our experiment resulted in three key findings: (1) removal of visual information increased the stochastic features of the postural sway variability, (2) the stochastic features were greater for the children with balance impairments, (3) the change in the amount of variability was strongly correlated with change the stochastic features. These results imply that the inability to suppress the stochastic features present in the nervous system may play a prominent role in the balance problems of children. Moreover, our results imply that alterations in the stochastic features drive the postural system away from successful balance strategies.
authors: Department of Physical Therapy, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, 985540 Nebraska Medical Center, Omaha, NE 68198-5450, USA. mkurz@unmc.edu
authors: Max J
authors: MJ
authors: Kurz
authors: David J
authors: DJ
authors: Arpin
authors: Brenda L
authors: BL
authors: Davies
authors: Regina
authors: R
authors: Harbourne
mesh_terms: D000222:Adaptation, Physiological; D002648:Child; D003198:Computer Simulation; D005260:Female; D005528:Foot / Q000502:physiology*; D017709:Fractals; D006801:Humans; D008297:Male; D008954:Models, Biological; D015233:Models, Statistical; D009068:Movement; D004856:Postural Balance; D011187:Posture; D011312:Pressure; D011597:Psychomotor Performance; D012678:Sensation Disorders / Q000503:physiopathology*; D013269:Stochastic Processes