title: Does proprioceptive acuity during active knee rotation in the transverse plane vary at different ranges?
abstract: BACKGROUND
  Knee proprioception in the sagittal plane has been widely investigated in prospective studies, however limited information is known about proprioceptive acuity during active knee rotation and the way most commonly injured.
  
  
  OBJECTIVE
  To investigate whether proprioceptive acuity during active internal and external knee rotation varies at different ranges in the transverse plane.
  
  
  METHODS
  Healthy volunteers (N: 26) without previous injury or surgery of the knee joint participated in the study.Knee rotation proprioceptive acuity was measured using a custom-designed device. The measure of proprioceptive acuity used in this study was the just-noticeable-difference (JND). Participants actively rotated the knee at different intervals(initial, mid, and terminal internal or external rotation range) to one of four movement blocks and the magnitude of the permitted motion was judged.
  
  
  RESULTS
  The means of the JND for proprioceptive acuity at initial internal rotation (0.80° ± 0.06) were significantly (p< 0.002) lower than for mid (1.62° ± 0.18), and terminal (2.08° ± 0.35) internal rotation. The means of the JND for proprioceptive acuity at initial external rotation (1.16° ± 0.10) were significantly (p< 0.04) lower than for mid (1.95° ± 0.30), and terminal (1.97° ± 0.24) internal rotation.
  
  
  CONCLUSIONS
  Participants perceived smaller differences between active internal and external rotation movements at initial rotation range than at the mid and terminal rotation range of movement. This suggests better proprioceptive acuity at the initial rotation range of movement in the transverse plane.
authors.forename: Qassim I
authors.initials: QI
authors.lastname: Muaidi
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D003430:Cross-Sectional Studies; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012399:Rotation; D055815:Young Adult
keywords: JND; Proprioception; knee; range intervals