title: Test-retest reliability of sudden ankle inversion measurements in subjects with healthy ankle joints.
abstract: BACKGROUND
  Sudden ankle inversion tests have been used to investigate whether the onset of peroneal muscle activity is delayed in patients with chronically unstable ankle joints. Before interpreting test results of latency times in patients with chronic ankle instability and healthy subjects, the reliability of these measures must be first demonstrated.
  
  
  OBJECTIVE
  To investigate the test-retest reliability of variables measured during a sudden ankle inversion movement in standing subjects with healthy ankle joints.
  
  
  METHODS
  Validation study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  15 subjects with healthy ankle joints (30 ankles).
  
  
  METHODS
  Subjects stood on an ankle inversion platform with both feet tightly fixed to independently moveable trapdoors. An unexpected sudden ankle inversion of 50 degrees was imposed.
  
  
  METHODS
  We measured latency and motor response times and electromechanical delay of the peroneus longus muscle, along with the time and angular position of the first and second decelerating moments, the mean and maximum inversion speed, and the total inversion time. Correlation coefficients and standard error of measurements were calculated.
  
  
  RESULTS
  Intraclass correlation coefficients ranged from 0.17 for the electromechanical delay of the peroneus longus muscle (standard error of measurement = 2.7 milliseconds) to 0.89 for the maximum inversion speed (standard error of measurement = 34.8 milliseconds).
  
  
  CONCLUSIONS
  The reliability of the latency and motor response times of the peroneus longus muscle, the time of the first and second decelerating moments, and the mean and maximum inversion speed was acceptable in subjects with healthy ankle joints and supports the investigation of the reliability of these measures in subjects with chronic ankle instability. The lower reliability of the electromechanical delay of the peroneus longus muscle and the angular positions of both decelerating moments calls the use of these variables into question.
authors.affiliation: Vrije Universiteit Brussel, Brussels, Belgium. christophe.eechaute@belgacom.net
authors.forename: Christophe
authors.initials: C
authors.lastname: Eechaute
authors.forename: Peter
authors.initials: P
authors.lastname: Vaes
authors.forename: William
authors.initials: W
authors.lastname: Duquet
authors.forename: Bart
authors.initials: B
authors.lastname: Van Gheluwe
mesh_terms: D000293:Adolescent; D000328:Adult; D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D004856:Postural Balance / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013180:Sprains and Strains / Q000503:physiopathology*