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Severity and Characteristics of Developmental Delay Can Be Assessed Using Variability Measures of Sitting Posture

Kyvelidou, Anastasia MS; Harbourne, Regina T. PT, PhD, PCS; Stergiou, Nicholas PhD

doi: 10.1097/PEP.0b013e3181ea75f1
Research Report

Purpose: We sought to identify measures of variability from sitting postural sway that are significantly different among infants who were developing typically, those who were developmentally delayed or hypotonic, and those who later on had a diagnosis of spastic or athetoid cerebral palsy.

Methods: Sixty-five infants were evaluated when they were just developing the ability to sit upright by assessing center of pressure (COP) data, using measures of both amount and temporal organization of COP variability.

Results: The results indicated that measures of variability of COP could discriminate between infants with developmental delay and infants with cerebral palsy and add to the description of sitting postural behavior.

Conclusions: Our method of evaluating sitting postural control could be an objective tool to help describe distinctive features of motor delay in an individual infant and could lead in the design of selective therapeutic interventions for improving postural control of infants with motor delays.

Supplemental digital content is available for this article. The authors present a method that can be used to differentiate postural sway characteristics of infants who are developing typically, those with developmental delay, and those with CP. The method, rooted in dynamical systems theory, has important implications for the manner in which therapists foster independent sitting.

Nebraska Biomechanics Core Facility, University of Nebraska at Omaha (Ms Kyvelidou and Dr Stergiou); Departments of Pediatrics (Ms Kyvelidou) and Environmental, Agricultural and Occupational Health Sciences, College of Public Health (Dr Stergiou); and Munroe-Meyer Institute (Dr Harbourne), University of Nebraska Medical Center, Omaha, Nebraska.

Correspondence: Nicholas Stergiou, PhD, University of Nebraska at Omaha, Omaha, NE 68182 (

Grant Support: This work was supported by National Institutes of Health (K25HD047194), NIDRR (H133G040118), and the Bukey and MacDonald Fellowship from the University of Nebraska Medical Center, Omaha.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (

© 2010 Lippincott Williams & Wilkins, Inc.