What goes round and round, up and down, left and right?  Answer: The shoulder joint.  Without a doubt the shoulder joint is the most versatile joint in the body.  No other joint comes close to the range of motion normally found in the shoulder or glenohumeral joint.

But there is a price to pay for such a tremendous range of motion.  The shoulder is very prone to problems as a result of overuse and muscle imbalances.  Just about everyone knows someone who has experienced problems in their shoulder.  In extreme cases the humerous (upper arm bone) can actually pop out of the socket.  Another common symptom of shoulder dysfunction is impingment syndrone or bursitus which is characterized by the inability to raise the arm above the head.

We often hear the term "rotator cuff" when referring to shoulder pain.  There actually is no muscle called a rotator cuff.  The rotator cuff is a general term that is refers to the confluence of four muscles attachment to the top of the humerous: supraspinatus, infraspinatus, teres minor and subscapularus.  The net effect of all these muscles at the top of the humerus is like a wrap or cuff around the bone.  Hence the name.  If you have the urge to remember these muscles SITS is the commonly used mnemonic device.

What is the importance of "rotator" in the rotator cuff.  Three of the four muscles impact the rotation of the humerus.  The infraspinatus and teres minor muscles provide for external rotation of the shoulder.  You can externally rotate your arm by hanging your left arm by your side and rotating your hand counter clockwise.

The subscapularus muscle internally rotates the arm.  You can internally rotate your arm by hanging your left arm by your side and rotating your hand clockwise.

The supraspinatus muscle is actually not a "rotator" at all.  This muscle is used to raise the arm above the head, or abduct the arm.  The supraspinatus is also the most commonly damaged muscle in the rotator cuff.

Why are there so many problems with the rotator cuff?

In a previous article we discussed the term boomeritus (baby boomers exercising more than any generation prior to them in order to retain their youth).  When the shoulder joint is repeatedly exercised, either incorrectly or in a pattern that creates muscle imbalances, problems with the rotator cuff will follow.  Here are some common faulty exercise patterns that can lead to rotator cuff problems:

1. Excessive use of the lateral raise.  Hang your arms at your side with 10-15 pound dumbbells in them.  Then raise your arms by extending them to the left and right to shoulder height.  This movement pattern strengthens the supraspinatus and medial deltoids.  Most folks that do this exercise too often are attempting to achieve the "cannonball" shoulders.  The error of the way happens when the other muscles in the rotator cuff are not trained as much as the supraspinatus.  Since all of the muscles in the rotator cuff attach to the scapula (shoulder blade), an imbalance in strength of the rotator cuff disturbs the scapula rhythm.  In other words, the should blade does not work right any more!
2. Overuse and incorrect technique when performing the bench press (see article The Glory of the Bench Press).  When the bar is lowered too low when performing the bench press the shoulder joint is stretched beyond its normal range.  The connection between the upper arm and shoulder joint is protected by a wrap of material call the shoulder capsule.  Think of the shoulder capsule as a wrapping of plastic shrink wrap around the joint.  One of the functions of this wrap is to maintain proper alignment of the humerus in the socket.  Lowering the barbell to the chest forces the shoulder capsule to be stretched.  After a while the shoulder capsule becomes stretched beyond repair.
3. Repetitive stress injuries...  Sports such as golf, tennis, baseball and football can place large forces on the shoulder joint.  After several hundred if not thousands of iterations of these ballistic throwing or rotating movements imbalances and injuries to the rotator cuffs can occur.
4. Wide grip chin-ups and lat pull-downs...  Wide grip chins and pull-downs can place tremendous forces through the shoulder girdle.  Use grip positions that are approximately shoulder width. 

What exercises can I do to provide a balanced strength pattern for my rotator cuff?  We use the following exercises extensively in-studio to provide balanced strength to the rotator cuff.  Remember, it's more important to strengthen the rotator cuff uniformly.  Failure to perform all of the exercises could easily create a muscle imbalance which will eventually lead to pain syndromes.

1. Sword Draw.  Place a small dumbbell in your right hand.  Pretend the dumbbell is the handle of a sword.  Place the dumbbell near the left hip pocket as if there is a sword in a holster.  Now draw the sword out of the holster by raising the hand across the body.  The right hand will end up above the right ear.
2. Internal Cable Pulls.  While sitting on a Swiss ball, place a cable handle in the hand closest to the cable pulley.  While keeping the elbow close to the side move the cable handle across the abdomen towards the midline of the body.  Slowly return the handle to the start position.
3. External Cable Pulls.  Using about half the weight of the internal cable pull, place the handle across the body in the hand furthest away from the pulley.  With the elbow tucked along the side pull the cable from the midline of the body to the outside of the the body across the abdomen.
4. Towel Stretch.  The towel stretch was first introduced to me by an orthopedic surgeon who was treating me with a bout of bursitis.  Instead of using a towel, I prefer to use a resistance tube.  Place the tube in the right hand and grab the tube with the left hand across the small of the back.  Pull the tubing up the right shoulder to stretch the left shoulder.

You don't need to be a golfer, racquet game player or throwing sport participant to benefit from a properly designed rotator cuff exercise program.  Good scapular rhythm and rotator cuff performance is important to perform every day routines such has hanging curtains, closing a window, and taking a glass off an upper cabinet shelf.