title: Postural adjustments in infants at very high risk for cerebral palsy before and after developing the ability to sit independently.
abstract: BACKGROUND
  Children with cerebral palsy (CP) have impaired postural control. Posture is controlled in two levels: direction-specificity, and fine-tuning of direction-specific adjustments, including recruitment order. Literature suggests that direction-specificity might be a prerequisite for independent sitting.
  
  
  OBJECTIVE
  To study development of postural adjustments in infants at very high risk for CP (VHR-infants) during developing the ability to sit independently.
  
  
  METHODS
  In a longitudinal study surface electromyograms of the neck-, trunk- and arm muscles of 11 VHR-infants and 11 typically developing (TD) infants were recorded during reaching in sitting before and after developing the ability to sit unsupported (median ages: VHR 8.0 and 14.9months; TD 5.7 and 10.4months). Sessions were video-recorded.
  
  
  RESULTS
  In VHR- and TD-infants the prevalence of direction-specific adjustments and recruitment order did not change when the infant learned to sit independently. In VHR-infants able to sit independently more successful reaching was associated with a higher frequency of bottom-up recruitment (Spearman's rho=0.828, p=0.006) and a lower frequency of simultaneous recruitment (Spearman's rho=-0.701, p=0.035), but not with more direction-specificity. In TD-infants not able to sit independently, more successful reaching was associated with higher rates of direction-specific adjustments at the neck level (Spearman's rho=0.778, p=0.014), but not with recruitment order.
  
  
  CONCLUSIONS
  In VHR- and TD-infants postural adjustments during reaching in terms of direction-specificity and recruitment order are not related to development of independent sitting. Postural adjustments are associated with success of reaching, be it in a different way for VHR- and TD-infants.
  
  
  BACKGROUND
  NTR1428.
authors: University of Groningen, University Medical Center Groningen, Dept. Paediatrics - Developmental Neurology, Groningen, The Netherlands.
authors: Anke G
authors: AG
authors: Boxum
authors: University of Groningen, University Medical Center Groningen, Dept. Paediatrics - Developmental Neurology, Groningen, The Netherlands.
authors: Lieke C
authors: LC
authors: van Balen
authors: University of Groningen, University Medical Center Groningen, Dept. Paediatrics - Developmental Neurology, Groningen, The Netherlands.
authors: Linze-Jaap
authors: LJ
authors: Dijkstra
authors: University of Groningen, University Medical Center Groningen, Dept. Paediatrics - Developmental Neurology, Groningen, The Netherlands.
authors: Elisa G
authors: EG
authors: Hamer
authors: University of Groningen, University Medical Center Groningen, Dept. Paediatrics - Developmental Neurology, Groningen, The Netherlands.
authors: Tjitske
authors: T
authors: Hielkema
authors: Rehabilitation Center 'Revalidatie Friesland', Beetsterzwaag, The Netherlands.
authors: Heleen A
authors: HA
authors: Reinders-Messelink
authors: University of Groningen, University Medical Center Groningen, Dept. Paediatrics - Developmental Neurology, Groningen, The Netherlands. Electronic address: m.hadders-algra@umcg.nl.
authors: Mijna
authors: M
authors: Hadders-Algra
mesh_terms: D002547:Cerebral Palsy / Q000503:physiopathology*; D002657:Child Development; D004576:Electromyography; D006801:Humans; D007223:Infant; D011187:Posture; D012307:Risk Factors
keywords: Cerebral palsy; EMG; High risk infants; Postural control; Reaching; Sitting