title: The effect of simulated scapular winging on glenohumeral joint translations.
abstract: OBJECTIVE
  In this study, we aim to test whether scapular winging results in a significant change in glenohumeral translation in the initial phase of the throwing motion.
  
  
  METHODS
  Six shoulders underwent an abbreviated throwing motion (ATM) from late cocking to the end of acceleration by use of a validated robotic system. The intact specimens were tested to establish a baseline. The position of the scapula was then affected to simulate scapular winging by placing a cylindrical wedge under the inferior angle of the scapula, and the ATM was performed again. For both conditions, the average glenohumeral translations and scapular rotations were plotted over time to calculate the area under the curve, as a representative of the overall glenohumeral translations and scapular rotations observed during the ATM.
  
  
  RESULTS
  Throughout the motion, the winged scapulae showed, on average, 7.7° more upward rotation, 1.6° more internal rotation, and 5.3° more anterior tipping as compared with the baseline. The scapular position relative to the hanging arm was significantly different between the baseline and scapular winging conditions in all arm positions, except for maximal external rotation and the neutral position. Comparing the area under the curve at baseline and with scapular winging indicated that scapular winging significantly increased anterior translation of the glenohumeral joint whereas translation in the superior/inferior and medial/lateral directions did not result in a change in translation.
  
  
  CONCLUSIONS
  These results may suggest a more important role of abnormalities in scapular position in predisposing throwing athletes to shoulder injuries of the anterior capsulolabral structures and consecutive glenohumeral instability.
authors: Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors: Andreas M
authors: AM
authors: Mueller
authors: Vahid
authors: V
authors: Entezari
authors: Claudio
authors: C
authors: Rosso
authors: Brett
authors: B
authors: McKenzie
authors: Andrew
authors: A
authors: Hasebrock
authors: Andrea
authors: A
authors: Cereatti
authors: Ugo
authors: U
authors: Della Croce
authors: Joseph P
authors: JP
authors: Deangelis
authors: Ara
authors: A
authors: Nazarian
authors: Arun J
authors: AJ
authors: Ramappa
mesh_terms: D001265:Athletic Injuries / Q000517:prevention & control; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D012372:ROC Curve; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D012540:Scapula / Q000002:abnormalities* / Q000503:physiopathology*; D012785:Shoulder Joint / Q000502:physiology*; D013177:Sports