title: Intrinsic predictors of lateral ankle sprain in adolescent dancers: a prospective cohort study.
abstract: OBJECTIVE
  To identify intrinsic predictors of lateral ankle sprain.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  A performing arts secondary school and a dance school.
  
  
  METHODS
  One hundred fifteen adolescent dancers (94 female and 21 male) entered the study. One ankle of each dancer was randomly assigned to a test group (n = 114), and the other was assigned to a validation group (n = 112).
  
  
  METHODS
  Eighteen measures, including age, dance history, previous ankle sprain, ankle and foot laxity and range of motion, and balance from test ankles were entered into a backwards stepwise Cox regression model. The model generated with the test group was used to predict ankle sprains in the validation group.
  
  
  METHODS
  Time to first lateral ankle sprain.
  
  
  RESULTS
  An increased risk of sprain in the test group was predicted by younger age [hazard ratio (HR) = 0.65, 95% CI 0.45-0.94], previous sprain of the contralateral ankle (HR = 3.76, CI 1.24-11.40), increased passive inversion range (HR = 1.06, CI 1.00-1.12), and inability to balance on demipointe (HR = 3.75, CI 1.02-13.73). Of these predictors, only previous sprain of the contralateral ankle significantly predicted ankle sprain in the validation group (HR = 3.90, CI 1.49-10.22). The predictive accuracy of this variable was not strong (positive likelihood ratio of 2.01 and negative likelihood ratio of 0.45).
  
  
  CONCLUSIONS
  A history of previous lateral ankle sprain is associated with an increase in the risk of future sprain of the contralateral ankle.
authors.affiliation: School of Physiotherapy, Faculty of Health Sciences, University of Sydney, Sydney, Australia.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Hiller
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Refshauge
authors.forename: Robert D
authors.initials: RD
authors.lastname: Herbert
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Kilbreath
mesh_terms: D000293:Adolescent; D016512:Ankle Injuries / Q000209:etiology*; D015331:Cohort Studies; D003615:Dancing / Q000293:injuries*; D005260:Female; D006801:Humans; D017844:Lateral Ligament, Ankle / Q000293:injuries*; D008297:Male; D009517:New South Wales; D011446:Prospective Studies; D018570:Risk Assessment; D013180:Sprains and Strains / Q000209:etiology* / Q000503:physiopathology