title: Effect of therapeutic exercise for hip osteoarthritis pain: results of a meta-analysis.
abstract: OBJECTIVE
  Recommendations for lower extremity osteoarthritis (OA) and exercise have been primarily based on knee studies. To provide more targeted recommendations for the hip, we gathered evidence for the efficacy of exercise for hip OA from randomized controlled trials.
  
  
  METHODS
  A bibliographic search identified trials that were randomized, controlled, completed by >or=60% of subjects, and involved an exercise group (strengthening and/or aerobic) versus a non exercise control group for pain relief in hip OA. Two reviewers independently performed the data extraction and contacted the authors when necessary. Effect sizes (ES) of treatment versus control and the I(2) statistic to assess heterogeneity across trials were calculated. Trial data were combined using a random-effects meta-analysis.
  
  
  RESULTS
  Nine trials met the inclusion criteria (1,234 subjects), 7 of which combined hip and knee OA; therefore, we contacted the authors who provided the data on hip OA patients. In comparing exercise treatment versus control, we found a beneficial effect of exercise with an ES of -0.38 (95% confidence interval [95% CI] -0.68, -0.08; P = 0.01), but with high heterogeneity (I(2) = 75%) among trials. Heterogeneity was caused by 1 trial consisting of an exercise intervention that was not administered in person. Removing this study left 8 trials (n = 493) with similar exercise strategy (specialized hands-on exercise training, all of which included at least some element of muscle strengthening), and demonstrated exercise benefit with an ES of -0.46 (95% CI -0.64, -0.28; P < 0.0001).
  
  
  CONCLUSIONS
  Therapeutic exercise, especially with an element of strengthening, is an efficacious treatment for hip OA.
authors.affiliation: Boston University, Boston, Massachusetts, USA.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Hernández-Molina
authors.forename: Stephan
authors.initials: S
authors.lastname: Reichenbach
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Michael
authors.initials: M
authors.lastname: Lavalley
authors.forename: David T
authors.initials: DT
authors.lastname: Felson