Strengthening of the Shoulder Muscles
The shoulder musculature combines two major abilities in the function of the upper limb, moderate strength and extreme mobility. The shoulder is the most mobile joint in the body and designed to allow us to put our hands anywhere we want in front of our visual field so we can perform often intricate actions. The shoulder socket is small and the ball of the upper arm bone is very large in comparison, making it the job of the shoulder muscles to place control and safely manage the placement of the two parts of the shoulder joint. The shoulder itself occurs between the scapula and the humerus, but two other joints make up the shoulder complex, the acromioclavicular joint and the scapulothoracic joint.
The four joints of the shoulder complex mean there are several groups of muscles which bear on the shoulder and must be considered when thinking about strengthening. They are the scapulothoracic muscles which originate mostly from the spine and ribs and attach to the shoulder blade, the rotator cuff muscles which originate from the shoulder blade and attach to the upper part of the arm bone, the deltoid muscle from the shoulder blade to the arm bone and the upper arm muscles which have part of their origins in the shoulder joint region.
Strengthening of the scapulothoracic muscles can be achieved by rowing and pushing movements with the arms, making the movements slow and steady to allow the muscles to work as hard as they can through the greatest range possible. The rotator cuff muscles work in general movements of the shoulder but can be isolated by performing internal rotation and external rotation of the shoulder with the arm in by the side. Supraspinatus strengthening is performed by doing dumbbell lateral raises but this can be an aggravating movement, leading to injury from impingement or supraspinatus tendinitis
The deltoid muscle functions to lift the arm up against gravity or with a weight and typical exercises are shoulder presses with a barbell or a dumbbell, exercises which are better controlled in a sitting position as standing can involve excessive body movement. The upper trapezius muscle, the large masses each side of the neck, can be trained by upright rowing or by a shrugging movement holding a barbell. Shoulder training needs to be balanced so that the strength and mobility of all the muscles groups is in proportion and so training needs to carefully planned and changed regularly.
Author: Jonathan Blood-Smyth