title: Decoupling of laxity and cortical activation in functionally unstable ankles during joint loading.
abstract: OBJECTIVE
  Recent studies have highlighted central nervous system alterations following ligamentous injury that may contribute to joint instability. However, research has not observed cortical responses to joint loading or sensory changes in the context of joint laxity following injury.
  
  
  METHODS
  Forty-two subjects were stratified into healthy (CON), unstable (UNS), and coper (COP) groups using ankle injury and instability history. Event-related desynchronization (%) from electroencephalography quantified somatosensory cortex activity as the ankle was loaded using an arthrometer.
  
  
  RESULTS
  Cortical activation increased as the ankle was loaded (F = 63.05, p < 0.001), but did not differ between groups (F = 1.387, p = 0.268), despite greater laxity in UNS (F = 3.58, p = 0.038).
  
  
  CONCLUSIONS
  Increased somatosensory cortex activity was observed with joint loading; however, though UNS demonstrated a degree of mechanical instability, no differences in magnitude of cortical activation were observed. Continued research should explore how the relationship between cortical activation and joint stiffness is affected following ligamentous injury.
authors: Department of Health and Exercise Science, Appalachian State University, ASU Box 32071, 111 Rivers Street, Boone, NC, 28604, USA, needlear@appstate.edu.
authors: Alan R
authors: AR
authors: Needle
authors: C Buz
authors: CB
authors: Swanik
authors: Michael
authors: M
authors: Schubert
authors: Kirsten
authors: K
authors: Reinecke
authors: William B
authors: WB
authors: Farquhar
authors: Jill S
authors: JS
authors: Higginson
authors: Thomas W
authors: TW
authors: Kaminski
authors: Jochen
authors: J
authors: Baumeister
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000294:innervation / Q000503:physiopathology*; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008297:Male; D013003:Somatosensory Cortex / Q000502:physiology*