An alternative correlation based feature for measuring step symmetry for assessing fall risk in elderly persons This publication appears in: Parkinsonism and Related Disorders Authors: B. Jansen, I. Bautmans, B. Van Keymolen, R. Deklerck and T. Mets Publication Date: Feb. 2010
Abstract: Background: In tri-axial trunk accelerometry for assessing fall risk, the most common protocol consists of walking a fixed distance (e.g. 18 m.) on a straight line. Autocorrelation-based step-symmetry is an often used feature.
Aim: To investigate differences in a new correlation-based feature in elderly according to fall risk.
Methods: Forty elderly (>=70 years old) with increased fall risk (history of falls and/or Timed-Get-Up-and-Go-Test >15s and/or Tinetti-test
Results: ICX0 is significantly different between the two groups (p=0.0017)in contrast to CC1 and CC2 (p=0.30 and p=0.77). However, |1- CC1| is significantly different (p=0.0015) as well as |1- CC2| (p=0.0018). Pearson's Correlation between CC1 and CC2 is low (R2=0.55). No significant relationship between ICX0 and CC1, CC2 or walking speed was found (respectively R2=0.017, R2=0.013 and R2=0.29).
Conclusions: We propose ICX0 as a new outcome for assessing fall risk in elderly persons, which seems independent of walking speed and - although conceptually similar -not related to craniocaudal step symmetry.
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