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The Rotator Cuff, by Matthew Romans

The rotator cuff is a group of four small muscles deep within the shoulder joint and below the major muscle of the shoulder joint, the deltoid. The supraspinatus holds the humerus (upper arm bone) in place. It originates above the spine of the scapula (shoulder blade) and inserts on the greater tuberosity of the humerus. The infraspinatus rotates and extends the shoulder. This muscle originates from the infraspinous fossa of the scapula and inserts into the posterior aspect of the greater tuberosity of the humerus. The teres minor rotates the arm away from the body. Its origin is the lateral scapula border and it inserts on the inferior aspect of the greater tuberosity of the humerus. Finally, the subscapularis holds the humerus to the scapula, and helps you to rotate, lower and hold your arm out straight. Its origin is the anterior surface of the scapula, and it inserts into the inferior aspect of the greater tuberosity of the humerus.

The shoulder joint (also known as the glenohumeral joint) is a ball-and-socket joint. As movement occurs, the "ball", or head of the humerus glides along the groove of the scapula (known as the glenoid fossa). The shoulder joint is very mobile, which is why you can move your arms in a number of different ways. Unfortunately this leaves the joint very unstable, and it can easily be injured. While acute injuries can occur as a result of a fall or some other trauma, the most common injuries to the rotator cuff are overuse injuries. Painters, cosmetologists, and athletes who throw (pitchers, quarterbacks, or javelin throwers) are particularly susceptible to overuse injuries of the rotator cuff. This could be something relatively minor like tendonitis and bursitis, or something more serious like impingement or a tear.

Another fact to keep in mind is that there is a natural imbalance between the functions of internal and external rotation of the humerus (rotating the upper arm toward and away from the midline of the body). While four muscles work to perform internal rotation (latissimus dorsi, teres major, pectoralis major, and anterior deltoid), only the infraspinatus and teres minor perform external rotation of the humerus. This natural muscular imbalance can leave the small muscles of the rotator cuff in a vulnerable position.

A complete tear of the rotator cuff will probably require surgery, depending on your age and lifestyle. An incomplete tear, inflammation, and impingement may simply require rest from the activity that is the cause of the problem. To protect your shoulder joint in general, you want to make the muscles surrounding the joint as strong as possible, and do so using an exercise protocol that is safe, slow, and low-force. At Total Results we specifically strengthen the rotator cuff by performing the External Rotation exercise using a Timed Static Contraction for 90 seconds (30 seconds each at 50%, 75%, and 100% effort), and the client provides manual resistance with their opposite hand. As a former college football quarterback who played in adult men's flag football leagues for nearly 20 years, I found that this exercise played a major role in preserving the health of my shoulder joint, and I performed it in every workout. We can also eliminate or modify certain exercises to work around rotator cuff injuries, such as altering the start position of the movement arm on the Chest Press or doing only horizontal exercises for the upper body.

While the rotator cuff makes up a very small percentage of your total muscle mass, these muscles can cause big problems if they are weak or injured. Let Total Results help you restore muscle and joint function, reduce pain, and protect against injury.

Posted July 16, 2019 by Tim Rankin