Functional anatomy of the shoulder complex.

Recent research findings are incorporated in this review of the functional anatomy of the shoulder complex. The scapulothoracic mechanism is described, including a review of scapular motion and the structure and function of the sternoclavicular and acromioclavicular joints. New information regarding the resting position of the scapula on the thorax and the effect of aging and spinal posture on position has been presented. In the second part of the paper, the anatomy of the glenohumeral joint is reviewed, with emphasis on the articular, periarticular, and muscular mechanisms responsible for stability of this articulation. The article concludes with a discussion of the integrated function of the scapulothoracic and glenohumeral articulations in upper extremity elevation.