title: Assessing hip abduction and adduction strength: can greater segmental fixation enhance the reproducibility?
abstract: OBJECTIVE
  To improve the reproducibility of testing hip abduction and adduction using an isokinetic dynamometer by a novel testing protocol.
  
  
  METHODS
  Test-retest design.
  
  
  METHODS
  Biodynamics laboratory.
  
  
  METHODS
  Fifteen healthy subjects (9 men, 6 women; age, 22.4+/-0.5 y) were recruited.
  
  
  METHODS
  Two setups were compared: the first according to manufacturer's guidelines (setup A) and the second a novel setup incorporating pelvic fixation (setup B). Setups A and B were performed in a random order. Both setups included the same battery of isokinetic (30 degrees/s, 60 degrees/s) and isometric tests, and were repeated 1 week later.
  
  
  METHODS
  The peak torque for each abduction and adduction exercise was noted and pelvic motion during testing was recorded.
  
  
  RESULTS
  Setup B significantly (P<.05) reduced transverse pelvic rotation by between 7.5 degrees and 8.0 degrees dependent on test speed. Mean differences for reproducibility of peak torque, ranged from 0.8 to 11.7 Nm. The coefficients of repeatability of both setups were similar, ranging from 21.4 to 56.3 Nm across isokinetic exercises. A similar observation was noted for isometric exercises, with the differences between the coefficients of repeatability ranging from 18.6 to 40.0 Nm.
  
  
  CONCLUSIONS
  Reducing pelvic rotation does not enhance reproducibility of the system and is not related to torque production. Further research is required to determine the optimal test setup.
authors.affiliation: Biosurgery and Surgical Technology, Division of Surgery, Oncology and Reproductive Medicine, Faculty of Medicine, Charing Cross Hospital, Imperial College London, UK.
authors.forename: Dhruvkumar
authors.initials: D
authors.lastname: Laheru
authors.forename: Jack C
authors.initials: JC
authors.lastname: Kerr
authors.forename: Alison H
authors.initials: AH
authors.lastname: McGregor
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000295:instrumentation; D005260:Female; D006615:Hip / Q000502:physiology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results