Abstract
Kyvelidou A, Harbourne RT, Shostrom VK, Stergiou N. Reliability of center of pressure
measures for assessing the development of sitting postural control in infants with
or at risk of cerebral palsy.
Objective
To establish the test-retest reliability of linear and nonlinear measures, including
intra- and intersession reliability, when used to analyze the center of pressure (COP)
time series during the development of infant sitting postural control in infants with
or at risk for cerebral palsy (CP).
Design
Longitudinal study.
Setting
University hospital laboratory.
Participants
Infants with or at risk for CP (N=18; mean age ± SD at entry into the study, 13.7±3.6mo).
Interventions
Not applicable.
Main Outcome Measures
Infant sitting COP data were recorded for 3 trials at each session (2 sessions for
each month within 1 week) for 4 consecutive months. The linear COP parameters of the
root mean square, the range of sway for both the anterior-posterior and the medial-lateral
directions, and the sway path were calculated. In addition, the nonlinear parameters
of approximate entropy, Lyapunov exponent (LyE), and the correlation dimension for
both directions were also calculated. Intra- and intersession reliability was computed
by the intraclass correlation coefficient (ICC).
Results
Regarding nonlinear measures, LyE showed high intra- and intersession ICC values in
comparison with all other parameters evaluated. Intrasession and intersession reliability
increased overall in the last 2 months of data collection and as sitting posture improved.
Conclusions
Our results suggested that the methodology presented is a reliable way of examining
the development of sitting postural control in infants with or at risk for CP, and
the reliability results generally parallel values found in sitting postural behavior
in typical infants. Therefore, this methodology may be helpful in examining efficacy
of therapy protocols directed at advancing sitting postural control in infants with
motor developmental delays.
Key Words
List of Abbreviations:
AP (anterior/posterior), ApEn (approximate entropy), COP (center of pressure), CP (cerebral palsy), ICC (intraclass correlation coefficient), LyE (Lyapunov exponent), ML (medial/lateral), RMS (root mean square)To read this article in full you will need to make a payment
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Article info
Footnotes
Supported by National Institutes of Health (grant no. K25HD047194), National Institute of Disability and Rehabilitation Research (grant no. H133G040118), the Nebraska Research Initiative, and the Bukey Fellowship and MacDonald Fellowship from University of Nebraska Medical Center.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.
Reprints are not available from the author.
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© 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
