It is no wonder we encounter so many shoulder issues! The shoulder joint, the most mobile, versatile and yet unstable joint in our body, is responsible for so much movement. Because your shoulder is a ball-and-socket joint, it has the ability to move in all directions. Just think how many ways you can move your arm.
The hip, knee and shoulder joints are generally considered to be our most important joints and they are all designed to balance stability with mobility. The American Medical Association tells us that a normal shoulder accounts for 60 percent of upper extremity function. With all this available range of motion, it is easy to see why the shoulder and its close neighbor, the rotator cuff, are vulnerable to injuries.
Dr. Michael Smith of Tampa Bay Orthopedic Specialists in Pinellas Park says, "Approximately half of my shoulder surgery is a result of rotator cuff injuries."
To remain in a stable condition, the shoulder depends on the muscles, ligaments and tendons to hold it in place. Your shoulder joints consist of three bones: the humerus (upper arm), the scapula (shoulder blades) and the clavicle (collar bone). Of the nine major muscles that act upon the shoulder, the two largest are the pectoralis major (chest muscle) in the front of the shoulder and the latissimus dorsi, the largest muscle in the back.
The strongest muscle of the shoulder, the deltoid muscle, sits like a cap on top of the shoulder and consists of three muscle heads:
Anterior deltoid, the front part of your deltoid, which when contracted allows you to move your arm away from your side toward the front.
Medial deltoid, located on the side of your delts, which when contracted enables you to lift your arm straight out to the sides.
Posterior deltoid is in the back, providing movement of the arm toward the back.
Four small but very important muscles surrounding the shoulder joint are the rotator cuff muscles. Together they rotate the shoulder joint and help maintain shoulder stability by preventing the arm from sliding out of its socket. During movement, they are the main stabilizers of the shoulder. Strengthening the rotator cuff will help prevent injuries such as tendonitis, rotator cuff tears and shoulder impingements.
According to Smith, the two most common rotator cuff injuries are a result of overuse or acute injuries such as a fall, heavy lifting or pulling with too forceful a movement.
If you are 50 or older and have not been exercising, check with your physician before beginning any exercise program. Write to Sally Anderson, a trainer, in care of LifeTimes, St. Petersburg Times, P.O. Box 1121, St. Petersburg, FL 33731.