title: Age-related changes in energy efficiency of gait, activity, and participation in children with cerebral palsy.
abstract: OBJECTIVE
  The aim of this study was to use a prospective longitudinal study to describe age-related trends in energy efficiency during gait, activity, and participation in ambulatory children with cerebral palsy (CP).
  
  
  METHODS
  Gross Motor Function Measure (GMFM), Paediatric Evaluation of Disability Inventory (PEDI), and Lifestyle Assessment Questionnaire-Cerebral Palsy (LAQ-CP) scores, and energy efficiency (oxygen cost) during gait were assessed in representative sample of 184 children (112 male; 72 female; mean age 10y 9mo; range 4-16y) with CP. Ninety-four children had unilateral spastic CP, 84 bilateral spastic CP, and six had other forms of CP. Fifty-seven were classified as Gross Motor Function Classification System (GMFCS) level I, 91 as level II, 22 as level III, and 14 as level IV). Assessments were carried out on two occasions (visit 1 and visit 2) separated by an interval of 2 years and 7 months. A total of 157 participants returned for reassessment.
  
  
  RESULTS
  Significant improvements in mean raw scores for GMFM, PEDI, and LAQ-CP were recorded; however, mean raw oxygen cost deteriorated over time. Age-related trends revealed gait to be most inefficient at the age of 12 years, but GMFM scores continued to improve until the age of 13 years, and two PEDI subscales to age 14 years, before deteriorating (p<0.05). Baseline score was consistently the single greatest predictor of visit 2 score. Substantial agreement in GMFCS ratings over time was achieved (κ(lw) =0.74-0.76).
  
  
  CONCLUSIONS
  These findings have implications in terms of optimal provision and delivery of services for young people with CP to maximize physical capabilities and maintain functional skills into adulthood.
authors.affiliation: School of Nursing and Midwifery, Queen's University Belfast, Belfast, Northern Ireland. c.kerr@qub.ac.uk
authors.forename: Claire
authors.initials: C
authors.lastname: Kerr
authors.forename: Brona C
authors.initials: BC
authors.lastname: McDowell
authors.forename: Jackie
authors.initials: J
authors.lastname: Parkes
authors.forename: Mike
authors.initials: M
authors.lastname: Stevenson
authors.forename: Aidan P
authors.initials: AP
authors.lastname: Cosgrove
mesh_terms: D000293:Adolescent; D000375:Aging; D002547:Cerebral Palsy / Q000150:complications* / Q000453:epidemiology / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D018672:Community Health Planning; D004185:Disability Evaluation; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D012044:Regression Analysis; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors