title: A clinical method for identifying scapular dyskinesis, part 1: reliability.
abstract: BACKGROUND
  Shoulder injuries are common in athletes involved in overhead sports, and scapular dyskinesis is believed to be one causative factor in these injuries. Many authors assert that abnormal scapular motion, so-called dyskinesis, is related to shoulder injury, but evidence from 3-dimensional measurement studies regarding this relationship is mixed. Reliable and valid clinical methods for detecting scapular dyskinesis are lacking.
  
  
  OBJECTIVE
  To determine the interrater reliability of a new test designed to detect abnormal scapular motion.
  
  
  METHODS
  Correlation design using ratings from multiple pairs of testers.
  
  
  METHODS
  University athletic training facilities.
  
  
  METHODS
  A sample of 142 athletes (from National Collegiate Athletic Association Divisions I and III) participating in sports requiring intense overhead arm use.
  
  
  METHODS
  Participants were videotaped from the posterior aspect while performing 5 repetitions of bilateral, weighted (1.4-kg [3-lb] or 2.3-kg [5-lb]) shoulder flexion and frontal-plane abduction. Videotapes from randomly chosen participants were subsequently viewed and independently rated for the presence of scapular dyskinesis by 6 raters (3 pairs), with each pair rating 30 different participants. Raters were trained to detect scapular dyskinesis using a self-instructional format with standardized operational definitions and videotaped examples of normal and abnormal motion.
  
  
  METHODS
  Scapular dyskinesis was defined as the presence of either winging or dysrhythmia. Right and left sides were rated independently as normal, subtle, or obvious dyskinesis. We calculated percentage of agreement and weighted kappa (kappa(w)) coefficients to determine reliability.
  
  
  RESULTS
  Percentage of agreement was between 75% and 82%, and kappa(w) ranged from 0.48 to 0.61.
  
  
  CONCLUSIONS
  The test for scapular dyskinesis showed satisfactory reliability for clinical use in a sample of overhead athletes known to be at increased risk for shoulder symptoms.
authors.affiliation: Arcadia University, Department of Physical Therapy, Glenside, PA 19038, USA. mcclure@arcadia.edu
authors.forename: Philip
authors.initials: P
authors.lastname: McClure
authors.forename: Angela R
authors.initials: AR
authors.lastname: Tate
authors.forename: Stephen
authors.initials: S
authors.lastname: Kareha
authors.forename: Dominic
authors.initials: D
authors.lastname: Irwin
authors.forename: Erica
authors.initials: E
authors.lastname: Zlupko
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000517:prevention & control*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D012090:Cumulative Trauma Disorders / Q000175:diagnosis; D020820:Dyskinesias / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D010147:Pain Measurement / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012540:Scapula / Q000502:physiology*; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000503:physiopathology*; D013177:Sports / Q000502:physiology; D013178:Sports Medicine / Q000379:methods; D014741:Video Recording; D055815:Young Adult