title: Isokinetic assessment of the shoulder rotators: a study of optimal test position.
abstract: BACKGROUND
  Isokinetic assessment of the shoulder rotator cuff is a common component of shoulder muscles assessment. Nevertheless, the extensive mobility of the shoulder poses great difficulty in finding a consensus protocol for evaluation.
  
  
  OBJECTIVE
  To select an optimal protocol, among three, based on the best reproducibility and reliability of strength scores derived from internal and external rotator tests.
  
  
  METHODS
  The dominant side external and internal rotator muscles of twelve healthy male subjects were evaluated based on a concentric protocol (60° s(-1) and 240° s(-1) ) in three different test positions: two in lying supine with the arm in either 90° or 45° abduction and one in the seated position with the arm moving in the scapular plane on the dominant shoulder. Subjects were tested twice over 10 days.
  
  
  RESULTS
  The two lying installations were associated with the lowest coefficient of variation (7.1-11.8%) and smallest detectable difference (7-15.9 N.m) for peak moment and strength ratios. Consequently, the lying positions were chosen for rotators assessment with 90° of abduction associated with a higher reproducibility for the agonist/antagonist ratios or 45° if some pain was provoked. In any case, the coefficient of variation did not exceed 12%.
  
  
  CONCLUSIONS
  Based on a reproducibility and reliability analysis, we recommend the testing of isokinetic strength of the shoulder rotators to be conducted in supine lying, with the arm at 90° or 45° abduction in the frontal plane.
authors.affiliation: Department of Motricity Sciences, University and CHU of Liege, Liege, Belgium. bforthomme@ulg.ac.be
authors.forename: B
authors.initials: B
authors.lastname: Forthomme
authors.forename: Z
authors.initials: Z
authors.lastname: Dvir
authors.forename: J M
authors.initials: JM
authors.lastname: Crielaard
authors.forename: J L
authors.initials: JL
authors.lastname: Croisier
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D006801:Humans; D007557:Israel; D008297:Male; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D011187:Posture; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D017006:Rotator Cuff / Q000502:physiology*; D012785:Shoulder Joint / Q000502:physiology*; D019415:Torque; D055815:Young Adult