Shoulder posture is not a case of "shoulders back and down!" [news]
Scapula positioning is vital for shoulder function and clients are often advised by the well-meaning therapists to “pull the shoulders back and down” for good posture. This has a number of problems attached. Firstly the action of bracing the shoulders back and down limits the mobility of the scapulae and therefore glenohumeral joint functionally. The scapula and glenohumeral joints should be stabilised using minimal effort, not bracing, while allowing movement at the same time. Secondly the muscles used for the "back and down" positioning are rhomboids (back) and latissimus dorsi (down), neither of which are key stabiliser muscles for the scapula. These muscles will downwardly rotate and depress the scapulae respectively. This can restrict scapula movement and cause impingement at end range flexion/abduction.