title: Reliability of isokinetic assessment of shoulder-rotator strength: a systematic review of the effect of position.
abstract: BACKGROUND
  Isokinetic assessment of shoulder internal-(IR) and external-rotator (ER) strength is commonly used with many different postures (sitting, standing, or supine) and shoulder positions (frontal or scapular plane with 45° or 90° of abduction).
  
  
  OBJECTIVE
  To conduct a systematic review to determine the influence of position on the intersession reliability of the assessment of IR and ER isokinetic strength, to identify the most reliable position, and to determine which isokinetic variable appears to be most stable in intersession reliability.
  
  
  METHODS
  A systematic literature search through MEDLINE and Pascal Biomed databases was performed in October 2009. Criteria for inclusion were that studies be written in English or French, describe the isokinetic evaluation methods, and describe statistical analysis.
  
  
  RESULTS
  Sixteen studies meeting the inclusion criteria were included. Variable reliability of ER and IR peak torque (PT) were generally reported for all assessment positions; intraclass correlation coefficients were .44-.98 in the seated position with 45° of shoulder abduction, .09-.77 in the seated position with 90° of shoulder abduction, .86-.99 (coefficient of variation: 7.5-29.8%) in the supine position with 90° of shoulder abduction, .82-.84 in the supine position with 45° of shoulder abduction, and .75-.94 in standing. The ER:IR ratio reliability was low for all positions.
  
  
  CONCLUSIONS
  The seated position with 45° of shoulder abduction in the scapular plane seemed the most reliable for IR and ER strength assessment. The standing position or a shoulder posture with 90° of shoulder abduction or in the frontal plane must be used with caution given the low reliability for peak torque. Good reliability of ER and IR PT was generally reported, but ER:IR ratio reliability was low.
authors.affiliation: Dept of Physical Medicine and Rehabilitation, University Hospital of Saint-Etienne, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Edouard
authors.forename: Pierre
authors.initials: P
authors.lastname: Samozino
authors.forename: Marc
authors.initials: M
authors.lastname: Julia
authors.forename: Sophie
authors.initials: S
authors.lastname: Gleizes Cervera
authors.forename: William
authors.initials: W
authors.lastname: Vanbiervliet
authors.forename: Paul
authors.initials: P
authors.lastname: Calmels
authors.forename: Vincent
authors.initials: V
authors.lastname: Gremeaux
mesh_terms: D006801:Humans; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D015203:Reproducibility of Results; D017006:Rotator Cuff / Q000502:physiology*; D012782:Shoulder / Q000502:physiology*