title: Ankle instability effects on joint position sense when stepping across the active movement extent discrimination apparatus.
abstract: BACKGROUND
  Individuals with and without functional ankle instability have been tested for deficits in lower limb proprioception with varied results.
  
  
  OBJECTIVE
  To determine whether a new protocol for testing participants' joint position sense during stepping  is reliable and can detect differences between participants with unstable and stable ankles.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  University clinical laboratory.
  
  
  METHODS
  Sample of convenience involving 21 young adult university students and staff. Ankle stability was categorized by score on the Cumberland Ankle Instability Tool; 13 had functional ankle instability, 8 had healthy ankles.
  
  
  METHODS
  Test-retest of ankle joint position  sense when stepping onto and across the Active Movement Extent Discrimination Apparatus twice, separated by an interim test, standing still on the apparatus and moving only 1 ankle into inversion.
  
  
  METHODS
  Difference in scores between  groups with stable and unstable ankles and between test repeats.
  
  
  RESULTS
  Participants with unstable ankles were worse at differentiating between inversion angles underfoot in both testing protocols. On repeated testing with the stepping protocol, performance of the group  with unstable ankles was improved (Cohen d = 1.06, P = .006), whereas scores in the stable ankle group did not change in the second test (Cohen d = 0.04, P = .899). Despite this improvement, the unstable group remained worse at differentiating inversion angles on the stepping  retest (Cohen d = 0.99, P = .020).
  
  
  CONCLUSIONS
  The deficits on proprioceptive tests shown by individuals with functional ankle instability improved with repeated exposure to the test situation. The learning effect may be the result of systematic exposure to ankle-angle  variation that led to movement-specific learning or increased confidence when stepping across the apparatus.
authors.affiliation: Australian Institute of Sport, Leverier Street, Bruce, Australia Capital Territory 2617, Australia. jeremy.witchalls@ausport.gov.au
authors.forename: Jeremy
authors.initials: J
authors.lastname: Witchalls
authors.forename: Gordon
authors.initials: G
authors.lastname: Waddington
authors.forename: Peter
authors.initials: P
authors.lastname: Blanch
authors.forename: Roger
authors.initials: R
authors.lastname: Adams
mesh_terms: D000328:Adult; D000842:Ankle / Q000503:physiopathology; D016512:Ankle Injuries; D000843:Ankle Joint / Q000502:physiology*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular; D013180:Sprains and Strains / Q000503:physiopathology*; D016138:Walking / Q000502:physiology; D055815:Young Adult