In CrossFit and in life, we go overhead. Kelly Starrett, of San Francisco CrossFit, explains the essential anatomy and physiology of the shoulder. This is an excerpt from his one day seminar on Training the Injured Athlete at CrossFit Santa Cruz on March 14th, 2009.
The shoulder is designed primarily for mobility. There are a number of forces that rotate it internally, while there are relatively few forces rotating externally. Balancing the shoulder so that it remains in an optimal position for maximum stability and force production is the goal.
In this video, Kelly explains how the shoulder works both when it is healthy and when there is an impingement.