A clinical method for identifying scapular dyskinesis, part 2: validity.
BACKGROUND
Although clinical methods for detecting scapular dyskinesis have been described, evidence supporting the validity of these methods is lacking.


OBJECTIVE
To determine the validity of the scapular dyskinesis test, a visually based method of identifying abnormal scapular motion. A secondary purpose was to explore the relationship between scapular dyskinesis and shoulder symptoms.


METHODS
Validation study comparing 3-dimensional measures of scapular motion among participants clinically judged as having either normal motion or scapular dyskinesis.


METHODS
University athletic training facilities.


METHODS
A sample of 142 collegiate athletes (National Collegiate Athletic Association Division I and Division III) participating in sports requiring overhead use of the arm was rated, and 66 of these underwent 3-dimensional testing.


METHODS
Volunteers were viewed by 2 raters while performing weighted shoulder flexion and abduction. The right and left sides were rated independently as normal, subtle dyskinesis, or obvious dyskinesis using the scapular dyskinesis test. Symptoms were assessed using the Penn Shoulder Score.


METHODS
Athletes judged as having either normal motion or obvious dyskinesis underwent 3-dimensional electromagnetic kinematic testing while performing the same movements. The kinematic data from both groups were compared via multifactor analysis of variance with post hoc testing using the least significant difference procedure. The relationship between symptoms and scapular dyskinesis was evaluated by odds ratios.


RESULTS
Differences were found between the normal and obvious dyskinesis groups. Participants with obvious dyskinesis showed less scapular upward rotation (P < .001), less clavicular elevation (P < .001), and greater clavicular protraction (P = .044). The presence of shoulder symptoms was not different between the normal and obvious dyskinesis volunteers (odds ratio = 0.79, 95% confidence interval = 0.33, 1.89).


CONCLUSIONS
Shoulders visually judged as having dyskinesis showed distinct alterations in 3-dimensional scapular motion. However, the presence of scapular dyskinesis was not related to shoulder symptoms in athletes engaged in overhead sports.
Tate
Angela R
AR
H/S Therapy Associates, Inc, Lower Gwynedd, PA, USA.
McClure
Philip
P
Kareha
Stephen
S
Irwin
Dominic
D
Barbe
Mary F
MF
D001265:Athletic Injuries / Q000517:prevention & control*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D016001:Confidence Intervals; D012090:Cumulative Trauma Disorders / Q000175:diagnosis; D020820:Dyskinesias / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010147:Pain Measurement / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; 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