File:Muscle recruitment.jpg

Figure: (A) Native shoulder. The center of rotation is in the humeral head, and the level of arm of deltoid does not allow deltoid recruitment. (B) Bony increased-offset reverse shoulder arthroplasty with lateral glenoid/medial humerus design. As in native shoulders, the bony lateralization of the center of rotation decreases recruitment of the deltoid for rotation. (C) Grammont reverse shoulder arthroplasty with humeral lateralization with a medial glenoid/lateral humerus design. Medialization of the center of rotation and humeral lateralization allows important deltoid recruitment. Reproduced from Collin et al., with permission.