title: Postural complexity influences development in infants born preterm with brain injury: relating perception-action theory to 3 cases.
abstract: OBJECTIVE
  Perception-action theory suggests a cyclical relationship between movement and perceptual information. In this case series, changes in postural complexity were used to quantify an infant's action and perception during the development of early motor behaviors.
  
  
  METHODS
  Three infants born preterm with periventricular white matter injury were included.
  
  
  RESULTS
  Longitudinal changes in postural complexity (approximate entropy of the center of pressure), head control, reaching, and global development, measured with the Test of Infant Motor Performance and the Bayley Scales of Infant and Toddler Development, were assessed every 0.5 to 3 months during the first year of life. All 3 infants demonstrated altered postural complexity and developmental delays. However, the timing of the altered postural complexity and the type of delays varied among the infants. For infant 1, reduced postural complexity or limited action while learning to control her head in the midline position may have contributed to her motor delay. However, her ability to adapt her postural complexity eventually may have supported her ability to learn from her environment, as reflected in her relative cognitive strength. For infant 2, limited early postural complexity may have negatively affected his learning through action, resulting in cognitive delay. For infant 3, an increase in postural complexity above typical levels was associated with declining neurological status.
  
  
  CONCLUSIONS
  Postural complexity is proposed as a measure of perception and action in the postural control system during the development of early behaviors. An optimal, intermediate level of postural complexity supports the use of a variety of postural control strategies and enhances the perception-action cycle. Either excessive or reduced postural complexity may contribute to developmental delays in infants born preterm with white matter injury.
authors.affiliation: S.C. Dusing, PT, PhD, Physical Therapy Department, Virginia Commonwealth University, PO Box 980224, 1200 E Broad St, Richmond, VA 23298 (USA). scdusing@vcu.edu.
authors.forename: Stacey C
authors.initials: SC
authors.lastname: Dusing
authors.affiliation: T. Izzo, PT, DPT, PCS, Physical Therapy Department, Virginia Commonwealth University.
authors.forename: Theresa
authors.initials: T
authors.lastname: Izzo
authors.affiliation: L.R. Thacker, PhD, Biostatistics Department, Virginia Commonwealth University.
authors.forename: Leroy R
authors.initials: LR
authors.lastname: Thacker
authors.affiliation: J.C. Galloway, PT, PhD, Department of Physical Therapy, University of Delaware, Newark, Delaware, and Department of Psychology, University of Delaware.
authors.forename: James Cole
authors.initials: JC
authors.lastname: Galloway
mesh_terms: D001930:Brain Injuries / Q000151:congenital* / Q000209:etiology; D002658:Developmental Disabilities / Q000209:etiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology; D012678:Sensation Disorders / Q000209:etiology*