title: Head-torso-hand coordination in children with and without developmental coordination disorder.
abstract: OBJECTIVE
  This study investigated the nature of coordination and control problems in children with developmental coordination disorder (DCD).
  
  
  METHODS
  Seven adults (two males, five females, age range 20-28 y; mean 23 y, SD 2 y 8 mo) and eight children with DCD (six males, two females, age range 7-9 y; mean 8 y, SD 8 mo), and 10 without DCD (seven males, three females, age range 7-9 y; mean 8 y, SD 7 mo) sat in a swivel chair and looked at or pointed to targets. Optoelectronic apparatus recorded head, torso, and hand movements, and the spatial and temporal characteristics of the movements were computed.
  
  
  RESULTS
  Head movement times were longer (p<0.05) in children with DCD than in the comparison group, even in the looking task, suggesting that these children experience problems at the lowest level of coordination (the coupling of synergistic muscle groups within a single degree of freedom). Increasing the task demands with the pointing condition affected the performance of children with DCD to a much greater extent than the other groups, most noticeably in key feedforward kinematic landmarks. Temporal coordination data indicated that all three groups attempted to produce similar movement patterns to each other, but that the children with DCD were much less successful than age-matched children in the comparison group.
  
  
  CONCLUSIONS
  Children with DCD have difficulty coordinating and controlling single degree-of-freedom movements; this problem makes more complex tasks disproportionately difficult for them. Quantitative analysis of kinematics provides key insights into the nature of the problems faced by children with DCD.
authors: College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, UK.
authors: Vera
authors: V
authors: Elders
authors: Sinéad
authors: S
authors: Sheehan
authors: Andrew D
authors: AD
authors: Wilson
authors: Martin
authors: M
authors: Levesley
authors: Bipin
authors: B
authors: Bhakta
authors: Mark
authors: M
authors: Mon-Williams
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002648:Child; D002675:Child, Preschool; D005260:Female; D006225:Hand / Q000503:physiopathology*; D006257:Head / Q000503:physiopathology*; D006801:Humans; D008297:Male; D019957:Motor Skills Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D004856:Postural Balance; D055815:Young Adult