The shoulder is the joint with the greatest range of motion in the human body. This joint receives its stability not through the solid, bony skeleton, but through a complex system of muscles, tendons, capsules, and ligaments. This gives the shoulder its fascinating mobility, but it also makes this joint vulnerable. However, successful research in recent years has tremendously improved our understanding of complex shoulder movements and the influence of each anatomic feature. Today, standardized operational shoulder treatment has evolved into a specialized surgical discipline. Modern medicine is now able to address the different age or injury related issues to which this joint is prone in a much more differentiated and effective manner.