title: Mechanical instability after an acute lateral ankle sprain.
abstract: OBJECTIVE
  To examine the natural recovery of mechanical laxity after an ankle sprain over an 8-week period.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Biodynamics research laboratory.
  
  
  METHODS
  Subjects with an acute lateral ankle sprain (n=16; 7 men, 9 women; age, 19.5+/-0.7y; mass, 64.6+/-8.1 kg; height, 171.9+/-9.6 cm) and healthy controls (n=16; 7 men, 9 women; age, 20.4+/-1.7y; mass, 76.9+/-11.1 kg; height, 176.5+/-11.1 cm) participated.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Subjects with acute ankle sprains were tested 3 days after injury and again 8 weeks later. Anterior and posterior displacement (mm) and inversion and eversion rotation ( degrees ) were measured with an instrumented arthrometer. For each dependent variable, a 2 x 2 x 2 repeated-measures multivariate analysis of variance was performed.
  
  
  RESULTS
  A significant interaction was found between group, time, and side for anterior translation (F=4.24, P=.05). There were also significant main effects for group. There was significantly more anterior displacement at day 3 (F=19.52, P=.001) and at week 8 (F=8.45, P=.010) in the injured group compared with the healthy group. There was also significantly more inversion rotation at day 3 (F=2.70, P=.002) and at week 8 (F=5.4, P=.033) in the injured group compared with the healthy group.
  
  
  CONCLUSIONS
  The lack of significant differences in mechanical laxity over an 8-week period suggests that natural recovery of laxity takes longer than 8 weeks. Further research needs to be conducted to examine how long this laxity persists and the role ankle rehabilitation plays in mechanical stability restoration.
authors: University of North Carolina Charlotte, Department of Kinesiology, Charlotte, NC 28223, USA. thubbar1@uncc.edu
authors: Tricia J
authors: TJ
authors: Hubbard
authors: Mitchell
authors: M
authors: Cordova
mesh_terms: D000208:Acute Disease; D000328:Adult; D016512:Ankle Injuries / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*; D000843:Ankle Joint / Q000503:physiopathology; D053587:Arthrometry, Articular; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D010146:Pain / Q000503:physiopathology; D011446:Prospective Studies; D013180:Sprains and Strains / Q000503:physiopathology / Q000534:rehabilitation*