title: On the use of sample entropy to analyze human postural sway data.
abstract: We analyze the irregularity of human postural sway data during quiet standing using the sample entropy (SampEn) algorithm. By considering recent methodological developments, we show that the SampEn parameter is able to characterize the irregularity of the center of pressure fluctuations through the analysis of the velocity variable. We present a practical method to select the input parameters of the SampEn algorithm. We show that the computed SampEn successfully discriminates two sensory conditions (eyes-open and eyes-closed) in a group of healthy young adults. We also perform surrogate data tests to investigate the nature of the underlying dynamics of our experimental data. Finally, the results of the proposed approach are compared to those obtained with the multiscale entropy algorithm.
authors.affiliation: EA 2991 Efficience et Déficience Motrices, Université de Montpellier I, 700, Av. du Pic St Loup, Montpellier, France. sofiane.ramdani@univ-montp1.fr
authors.forename: Sofiane
authors.initials: S
authors.lastname: Ramdani
authors.forename: Benoît
authors.initials: B
authors.lastname: Seigle
authors.forename: Julien
authors.initials: J
authors.lastname: Lagarde
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bouchara
authors.forename: Pierre Louis
authors.initials: PL
authors.lastname: Bernard
mesh_terms: D000465:Algorithms; D003627:Data Interpretation, Statistical; D006801:Humans; D011187:Posture; D011312:Pressure; D014796:Visual Perception; D055815:Young Adult