title: Strength-training protocols to improve deficits in participants with chronic ankle instability: a randomized controlled trial.
abstract: BACKGROUND
  Although lateral ankle sprains are common in athletes and can lead to chronic ankle instability (CAI), strength-training rehabilitation protocols may improve the deficits often associated with CAI.
  
  
  OBJECTIVE
  To determine whether strength-training protocols affect strength, dynamic balance, functional performance, and perceived instability in individuals with CAI.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  Athletic training research laboratory.
  
  
  METHODS
  A total of 39 individuals with CAI (17 men [44%], 22 women [56%]) participated in this study. Chronic ankle instability was determined by the Identification of Functional Ankle Instability Questionnaire, and participants were randomly assigned to a resistance-band-protocol group (n = 13 [33%] age = 19.7 ± 2.2 years, height = 172.9 ± 12.8 cm, weight = 69.1 ± 13.5 kg), a proprioceptive neuromuscular facilitation strength-protocol group (n = 13 [33%], age = 18.9 ± 1.3 years, height = 172.5 ± 5.9 cm, weight = 72.7 ± 14.6 kg), or a control group (n = 13 [33%], age = 20.5 ± 2.1 years, height = 175.2 ± 8.1 cm, weight = 70.2 ± 11.1 kg).
  
  
  METHODS
  Both rehabilitation groups completed their protocols 3 times/wk for 6 weeks. The control group did not attend rehabilitation sessions.
  
  
  METHODS
  Before the interventions, participants were pretested by completing the figure-8 hop test for time, the triple-crossover hop test for distance, isometric strength tests (dorsiflexion, plantar flexion, inversion, and eversion), the Y-Balance test, and the visual analog scale for perceived ankle instability. Participants were again tested 6 weeks later. We conducted 2 separate, multivariate, repeated-measures analyses of variance, followed by univariate analyses on any significant findings.
  
  
  RESULTS
  The resistance-band protocol group improved in strength (dorsiflexion, inversion, and eversion) and on the visual analog scale (P < .05); the proprioceptive neuromuscular facilitation group improved in strength (inversion and eversion) and on the visual analog scale (P < .05) as well. No improvements were seen in the triple-crossover hop or the Y-Balance tests for either intervention group or in the control group for any dependent variable (P > .05).
  
  
  CONCLUSIONS
  Although the resistance-band protocol is common in rehabilitation, the proprioceptive neuromuscular facilitation strength protocol is also an effective treatment to improve strength in individuals with CAI. Both protocols showed clinical benefits in strength and perceived instability. To improve functional outcomes, clinicians should consider using additional multiplanar and multijoint exercises.
authors.affiliation: School of Public Health, Indiana University, Bloomington;
authors.forename: Emily A
authors.initials: EA
authors.lastname: Hall
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Docherty
authors.forename: Janet
authors.initials: J
authors.lastname: Simon
authors.forename: Jackie J
authors.initials: JJ
authors.lastname: Kingma
authors.forename: Joanne C
authors.initials: JC
authors.lastname: Klossner
mesh_terms: D016512:Ankle Injuries / Q000503:physiopathology / Q000534:rehabilitation; D000843:Ankle Joint / Q000503:physiopathology; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000534:rehabilitation*; D008297:Male; D004856:Postural Balance / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult
keywords: Star Excursion Balance Test; functional ankle instability; functional performance; rehabilitation