Author/Authors :
Nishinaka، نويسنده , , Naoya and Tsutsui، نويسنده , , Hiroaki and Mihara، نويسنده , , Kenichi and Suzuki، نويسنده , , Kazuhide and Makiuchi، نويسنده , , Daisuke and Kon، نويسنده , , Yoshiaki and Wright، نويسنده , , Thomas W. and Moser، نويسنده , , Michael W. and Gamada، نويسنده , , Kazuyoshi and Sugimoto، نويسنده , , Hideharu and Banks، نويسنده , , Scott A.، نويسنده ,
Abstract :
The purpose of this study was to investigate glenohumeral translation in-vivo during active shoulder abduction in the scapular plane. Three-dimensional (3D) models of 9 shoulders were created from CT scans. Fluoroscopic views aligned to the plane of the scapula were recorded during active arm abduction with neutral rotation. 3D motions were determined using model-based 3D-to-two-dimensional (2D) registration. Humeral translation was referenced to the glenoid center in the superior/inferior direction. The humerus moved an average of 1.7 mm superior with arm abduction, from an inferior location to the glenoid center. The humeral head was centered within 1 mm from the glenoid center above 80° abduction. Variability in glenohumeral translation between shoulders decreased significantly from initial to final arm abduction. Our findings agree with some authorsʹ observations of inferior-to-central translation of the humerus and behavior as a congruent ball and socket. We believe this information will help improve the understanding of shoulder function.
