title: Test-Retest repeatability of gluteus maximus strength testing using a fixed digital dynamometer in children with cerebral palsy.
abstract: OBJECTIVE
  To investigate the test-retest repeatability of the measurement of the gluteus maximus strength using a fixed digital dynamometer.
  
  
  METHODS
  Test-retest design. The strength of the gluteus maximus was measured in prone position during 2 sessions an average of 6 days apart.
  
  
  METHODS
  Gait analysis laboratory.
  
  
  METHODS
  Eleven children with spastic diplegic (n=10) and hemiplegic (n=1) cerebral palsy (CP), age 6 to 14 years, and 11 aged-matched children. All were able to walk independently, but 2 in the CP group used walking aids.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  On 2 occasions, gluteus maximus strength was measured 3 times in 2 positions of the hip joint. Repeatability of the measurements was assessed by intraclass correlation coefficients (ICCs), coefficients of variation, and the coefficient of repeatability.
  
  
  RESULTS
  When normalized to body mass, children with CP had significantly less gluteus maximus strength compared with the controls. The ICCs for the control group ranged from .76 to .85 and from .75 to .83 for the involved leg in the CP group.
  
  
  CONCLUSIONS
  The reliability of measurement of gluteus maximus strength was good for both control group and the involved leg of the CP group. The normalized values for gluteus maximus strength and measures of reproducibility can be used when measuring gluteus maximus strength in children with CP.
authors.affiliation: Anderson Gait Analysis Laboratory, Eastern General Hospital, Edinburg, Scotland, UK. mvandderlinden@qmuc.ac.uk
authors.forename: Mariëtta L
authors.initials: ML
authors.lastname: van der Linden
authors.forename: Alison M
authors.initials: AM
authors.lastname: Aitchison
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Hazlewood
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Hillman
authors.forename: James E
authors.initials: JE
authors.lastname: Robb
mesh_terms: D000293:Adolescent; D002081:Buttocks; D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000503:physiopathology*; D002648:Child; D003627:Data Interpretation, Statistical; D006801:Humans; D018482:Muscle, Skeletal / Q000503:physiopathology*; D026741:Physical Therapy Modalities / Q000295:instrumentation*; D016684:Prone Position / Q000502:physiology; D015203:Reproducibility of Results