title: Recovery From a First-Time Lateral Ankle Sprain and the Predictors of Chronic Ankle Instability: A Prospective Cohort Analysis.
abstract: BACKGROUND
  Impairments in motor control may predicate the paradigm of chronic ankle instability (CAI) that can develop in the year after an acute lateral ankle sprain (LAS) injury. No prospective analysis is currently available identifying the mechanisms by which these impairments develop and contribute to long-term outcome after LAS.
  
  
  OBJECTIVE
  To identify the motor control deficits predicating CAI outcome after a first-time LAS injury.
  
  
  METHODS
  Cohort study (diagnosis); Level of evidence, 2.
  
  
  METHODS
  Eighty-two individuals were recruited after sustaining a first-time LAS injury. Several biomechanical analyses were performed for these individuals, who completed 5 movement tasks at 3 time points: (1) 2 weeks, (2) 6 months, and (3) 12 months after LAS occurrence. A logistic regression analysis of several "salient" biomechanical parameters identified from the movement tasks, in addition to scores from the Cumberland Ankle Instability Tool and the Foot and Ankle Ability Measure (FAAM) recorded at the 2-week and 6-month time points, were used as predictors of 12-month outcome.
  
  
  RESULTS
  At the 2-week time point, an inability to complete 2 of the movement tasks (a single-leg drop landing and a drop vertical jump) was predictive of CAI outcome and correctly classified 67.6% of cases (sensitivity, 83%; specificity, 55%; P = .004). At the 6-month time point, several deficits exhibited by the CAI group during 1 of the movement tasks (reach distances and sagittal plane joint positions at the hip, knee and ankle during the posterior reach directions of the Star Excursion Balance Test) and their scores on the activities of daily living subscale of the FAAM were predictive of outcome and correctly classified 84.8% of cases (sensitivity, 75%; specificity, 91%; P < .001).
  
  
  CONCLUSIONS
  An inability to complete jumping and landing tasks within 2 weeks of a first-time LAS and poorer dynamic postural control and lower self-reported function 6 months after a first-time LAS were predictive of eventual CAI outcome.
authors.affiliation: School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland cailbhe.doherty@ucdconnect.ie.
authors.forename: Cailbhe
authors.initials: C
authors.lastname: Doherty
authors.affiliation: Sport and Exercise Sciences Research Institute, Ulster Sports Academy, University of Ulster, Newtownabbey, Co. Antrim, Northern Ireland.
authors.forename: Chris
authors.initials: C
authors.lastname: Bleakley
authors.affiliation: Department of Kinesiology, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Hertel
authors.affiliation: School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.
authors.forename: Brian
authors.initials: B
authors.lastname: Caulfield
authors.affiliation: St Vincent's University Hospital, Dublin, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Ryan
authors.affiliation: School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland Institute for Sport and Health, University College Dublin, Dublin, Ireland.
authors.forename: Eamonn
authors.initials: E
authors.lastname: Delahunt
mesh_terms: D000328:Adult; D016512:Ankle Injuries / Q000503:physiopathology*; D000843:Ankle Joint / Q000503:physiopathology*; D001696:Biomechanical Phenomena / Q000502:physiology; D015331:Cohort Studies; D004185:Disability Evaluation; D005080:Exercise Test; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008297:Male; D004856:Postural Balance / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012680:Sensitivity and Specificity; D013180:Sprains and Strains / Q000503:physiopathology*; D055815:Young Adult
keywords: ankle instability; ankle joint; biomechanical phenomena; kinematics; kinetics; postural balance