title: Test-retest reliability of isokinetic dynamometry for the assessment of spasticity of the knee flexors and knee extensors in children with cerebral palsy.
abstract: OBJECTIVE
  To assess test-retest reliability of the peak resistance torque and slope of work methods of spasticity measurement of the knee flexors and extensors in children with cerebral palsy (CP).
  
  
  METHODS
  Test-retest reliability study.
  
  
  METHODS
  Pediatric orthopedic hospital.
  
  
  METHODS
  Fifteen children with CP.
  
  
  METHODS
  Knee extensor and flexor spasticity was assessed with an isokinetic dynamometer using passive movements at 15 degrees, 90 degrees, and 180 degrees/s taken 1 hour apart.
  
  
  METHODS
  Peak resistive torque and work were calculated. The relative and absolute test-retest reliability was calculated by using intraclass correlation coefficients (ICCs) and Bland-Altman plots, respectively.
  
  
  RESULTS
  Relative reliability was good (ICC>.75) for slope-of-work and peak resistance torque measurements at a velocity of 180 degrees/s, whereas reliability of peak torque measurements was decreased (ICC<.51) at slower velocities for both muscle groups. The 95% limits of agreement of Bland-Altman plots contained most data points for both methods, but the width of the limits of agreement were wide.
  
  
  CONCLUSIONS
  The measurement of spasticity of the knee extensors and flexors in children with CP using peak-resistance torque at 180 degrees/s and the slope of work method has acceptable relative test-retest reliability. However, the absolute reliability of spasticity data should be considered cautiously.
authors.affiliation: Research Department, Shriners Hospitals for Children in Philadelphia 19140, and Institute for Physical Therapy Education, Widener University, Chester, PA, USA. srpierce@mail.widener.edu
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Pierce
authors.forename: Richard T
authors.initials: RT
authors.lastname: Lauer
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Shewokis
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Rubertone
authors.forename: Margo N
authors.initials: MN
authors.lastname: Orlin
mesh_terms: D000293:Adolescent; D002547:Cerebral Palsy / Q000150:complications / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007717:Knee / Q000503:physiopathology*; D008297:Male; D009128:Muscle Spasticity / Q000209:etiology / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology; D012046:Rehabilitation / Q000295:instrumentation*; D015203:Reproducibility of Results; D019415:Torque