A clinical method for identifying scapular dyskinesis, part 1: reliability.
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.
McClure
Philip
P
Arcadia University, Department of Physical Therapy, Glenside, PA 19038, USA. mcclure@arcadia.edu
Tate
Angela R
AR
Kareha
Stephen
S
Irwin
Dominic
D
Zlupko
Erica
E
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