[직/편성물] Dynamic Analysis of Posture Profiles in Quiet Stance on Carpets through Fractional Brownian Motion 출판일 : 2008.01.01 저자 : Jianhua Wu, Ning Pan, and Keith R. Williams 서지사항 : Textile Research Journal, Volume 78, Issue 1, 45페이지 등록일 : 2011.06.27 I 조회수 : 673 작성자 : admin |
In this study we examine the dynamic characteristics of the center of pressure (COP)
profiles in quiet stance on various carpets through the framework of fractional Brownian
motion. Four different carpets plus the force platform (which served as a control floor) were
tested. Six healthy young subjects stood stationary in bare feet on each flooring condition
under both eyes-open (EO) and eyes-closed (EC) conditions. A stabilogram diffusion
analysis (SDA) was conducted in both anteroposterior and mediolateral directions to extract
the dynamic features of the COP profiles. Two approximately linear regions (short-versus
long-term regions) were found for all of the flooring conditions in the double logarithmic plot
of the mean-square displacements versus time intervals, implying that a two-stage control
scheme exists in regulating the posture. In general, a more compliant carpet was found to
be associated with a shorter transitional time interval and a lower H L value (Hurst
coefficient in the long-term region) under the EO condition, but to be correlated with a
higher H S (Hurst coefficient in the short-term region) and a higher H L under the EC
condition. While the hard floor of the force platform significantly decreased H L from the EO
to the EC conditions, the alteration of visual environments did not substantially influence H L
for a compliant carpet.
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