Build Big Rotator Cuff

The Rotator Cuff

Discussing the rotator cuff! the shoulder joint has an extremely wide range of motion. A key structure supporting the shoulder joint is the rotator cuff. The rotator cuff is concerned with two major functions, rotating the shoulder and cuffing the joint . Rotation may not appear as an obvious movement with regard to the shoulder.

To visualize shoulder rotation, place your arm at your side and bend the elbow to 90o, as if to shake hands, but maintain the upper arm against your side and keep you palm in (thumb up).

Keeping your upper arm against your side, bring your forearm and hand across your body to rest your palm on your stomach. That movement is internal shoulder rotation (the upper arm bone, the humerus, is rotating relative to the shoulder; internal is used to denote a movement towards the midline of the body). A more extreme form of internal rotation is to place the back of your hand on the small of your back, again with your elbow bent at 90o. Now keeping your elbow bent, lift your hand away from your body. One muscle of the rotator cuff, subscapularis arises from the underneath side of the shoulder blade (the side against the rib cage) and attaches to the humerus in such a way as to produce rotation of the humerus when contracted.

If the lifting of your hand away from your back produces extreme pain or is simply impossible to perform, injury to this muscle (or a tear in its tendon) may be the source. This problem requires medical attention. The opposite motion to internal rotation is external rotation (rotating your forearm away from your stomach with your upper arm against your side) and is produced by contracting two other muscles of the rotator cuff group, infraspinatus and teres minor. These muscles also arise from the shoulder blade, but on the outer side, and also attach to the humerus.

These three muscles are responsible for shoulder rotation, but the rotator cuff complex has four muscles and this is where the cuff component is involved. The fourth muscle is called supraspinatus and arises over the top of the shoulder blade (in the supraspinous fossa) and crosses the shoulder joint traveling underneath the acromion and attaching to the humerus just below the humeral head. Altogether, these four muscles (the three true rotators and supraspinatus) are the innermost set of muscles surrounding the shoulder joint and form a cuff around the joint.

Bearing in mind the shallow nature of the glenoid fossa and the propensity for the humeral head to dislocate, the contraction of all four muscles forms a tight wall around the lip of the socket to help hold the humeral head in position (centered in the glenoid fossa) 5. During almost any shoulder movement, these muscles are contracting to stabilize the joint throughout the movement by maintaining the humeral head centered in the glenoid fossa .

When you throw an object, the entire movement is designed to throw your arm away from your body. The object is thrown because you release your grip on it. Your arm and shoulder joint stay in place because the rotator cuff is holding the upper arm bone in place. This is why rotator cuff injuries are so devastating to baseball pitchers; a strong, intact rotator cuff is needed to allow for high velocity pitches without injuring the shoulder joint. Weakness or worse, injury to the rotator cuff can place undue stress on the shoulder joint during heavy lifting routines (because the humeral head does not stay centered in the glenoid fossa).

Strengthening the rotator cuff muscles, particularly the three involved with rotation is straightforward and basically involves movements as described above for internal and external rotation, but with light weights while lying on your side. The remaining muscle, the supraspinatus, is less straightforward and unfortunately, much advice over the years has served to compound problems , especially for those who are anatomically predisposed to have problems in the first place.