Measurement, 51(1), 124–132p. (2014) DOI:10.1016/j.measurement.2014.02.009

Intra-session reliability of traditional and nonlinear time-series posturographic measures in a semi-tandem stance: A reference to age

G. Markovic, P. Mikulic, H. Kern, N. Sarabon

The purpose of this study was to evaluate the intra-session reliability of traditional and nonlinear time-series center of pressure (CoP) based measures of postural sway during upright semi-tandem quiet stance in young vs. older subjects. Seventy-four healthy volunteers (40 young individuals, mean age: 27 ± 6 yrs; 34 older individuals, mean age: 79 ± 8 yrs) performed three 30-s trials of semi-tandem quiet stance on a force plate with their eyes open. Traditional posturography analysis and 4 nonlinear time-series analyses (sway density plots, diffusion plots, recurrence quantification, sample entropy analyses) were applied to the recorded CoP time series, based on which 13 traditional and 32 nonlinear time-series CoP-based measures were calculated. Significant trial-to-trial improvements (particularly between the first and second trial) were observed in the calculated CoP measures in only 2 and 4 cases in the young and older individuals respectively. Regarding the traditional CoP measures, the highest intraclass correlation coefficients (ICCaverage, i.e. ICC2,k) (0.75-0.96) and the lowest coefficients of variation (CV) (8.2-27.3%) in both age groups were observed in the mean frequency of CoP local extrema, the mean amplitude of CoP excursion, and the time-normalized CoP area, although for some of the measures we recommend an additional familiarization trial due to systematic bias. Regarding the structural mechanics CoP measures, the highest ICCa (0.70-0.94) and the lowest CVs (1.2-8.4%) in both age groups were observed in those derived from recurrence quantification and sample entropy analyses, respectively. These CoP measures could be recommended for further use in basic and clinical studies, particularly those on age-related changes in postural control during the semi-tandem quiet stance.

back


Creative Commons License © 2017 SOME RIGHTS RESERVED
The content of this web site is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Germany License.

Please note: The abstracts of the bibliography database may underly other copyrights.

Ihr Browser versucht gerade eine Seite aus dem sogenannten Internet auszudrucken. Das Internet ist ein weltweites Netzwerk von Computern, das den Menschen ganz neue Möglichkeiten der Kommunikation bietet.

Da Politiker im Regelfall von neuen Dingen nichts verstehen, halten wir es für notwendig, sie davor zu schützen. Dies ist im beidseitigen Interesse, da unnötige Angstzustände bei Ihnen verhindert werden, ebenso wie es uns vor profilierungs- und machtsüchtigen Politikern schützt.

Sollten Sie der Meinung sein, dass Sie diese Internetseite dennoch sehen sollten, so können Sie jederzeit durch normalen Gebrauch eines Internetbrowsers darauf zugreifen. Dazu sind aber minimale Computerkenntnisse erforderlich. Sollten Sie diese nicht haben, vergessen Sie einfach dieses Internet und lassen uns in Ruhe.

Die Umgehung dieser Ausdrucksperre ist nach §95a UrhG verboten.

Mehr Informationen unter www.politiker-stopp.de.