About the structure of posturography: Sampling duration, parametrization, focus of attention (part II)

Abstract

There exists a great variety of posturographic parameters which complicates the evaluation of center of pressure (COP) data. Hence, recommendations were given to use a set of complementary parameters to explain most of the variance. However, it is unknown whether a dual task paradigm leads to different parametrization sets. On account of this problem an exploratory factor analysis approach was conducted in a dual task experiment. 16 healthy subjects stood on a force plate performing a posture-cognition dual task (DT, focus of attention on a secondary task) with respect to different sampling durations. The subjects were not aware of being measured in contrast to a baseline task condition (BT, internal focus of attention) in the previously published part I. In compareson to BT a different factor loading pattern appears. In addition, factor loadings are strongly affected by different sampling durations. DT reveals a change of factor loading structure with longer sampling durations compared to BT. Specific recommendations concerning a framework of posturographic parametrization are given.

Validation of Different Filters for Center of Pressure Measurements by a Cross-Section Study

“…In previous studies, the special influence of the measurement time on the frequency-dependent parameters has already been proven [7]. Several studies have already shown that 95% of the frequency components of the CoP's are below 1 Hz [7,17]. This finding coincides with the results of Durate and Zatsiorsky, among others.…”

“…It could be seen that a longer measurement time produces more reliable results and is therefore preferable. Based on the findings of this study, they recommended using a measurement period of at least 120 s. If the test setup allows, if possible, even a measurement period of 300 s should be chosen [17].…”

“…Funding: The present study was funded by the German Federal Institute of Sport Science (http://www.bisp.de). The research was realized within the project RAN Rücken (ZMVI1-080102A/ [11][12][13][14][15][16][17][18]. Funding was received by PP.…”

Bioceramic fabrics improve quiet standing posture and handstand stability in expert gymnasts

“…Movements of the CoP were calculated with Matlab 7.8 (MathWorks) following to the recommendations of Schubert et al [10]. For each participant, suit condition, and dependent variable, the mean value and the standard deviation of the mean were computed.…”

Visiting Richard Serra’s “Promenade” sculpture improves postural control and judgment of subjective visual vertical

“…The duration of posturography recording is not standardized. While short durations (typically 30 s) are commonly used in clinics, longer durations might allow more discriminative power on non-linear parameters ( Schubert et al, 2012a , b ). Our 51.2-s recording is thus a compromise between short recordings avoiding the occurrence of transient and particular events due to postural changes and consequently deteriorating measures related to sway area, and long recordings allowing a better accuracy in time-frequency analysis.…”