The shoulder is an area that is particularly susceptible to injury. The shoulder actually consists of four separate joints, each with ligaments that maintain its integrity. When these ligaments are lax or when underlying muscles are weak, function at these joints is affected and overuse injury is inevitable.
The head of the humerus (upper arm bone) rotates in the glenoid fossa of the scapula (shoulder blade) as movement of the arm at the shoulder (glenohumeral joint) occurs. Because movement range at this joint is considerable and the joint space is small, the humeral head comes close to the supraspinatus tendon of the rotator cuff as the arm is raised. As a result, instability can cause this tendon to be impinged, a condition that will lead to tendinitis and eventual tearing.
There are two types of impingement that initiate this cycle. Primary impingement is caused by repetitive overhead activity and is common in sports that involve swinging a racquet and occupations that keep the arm in a constantly raised position (painters and electricians). Once primary impingement is present, the overhead posture must be avoided to allow healing to occur. Secondary impingement is caused by weakened muscles and ligaments (the connective tissue that connects bone to bone).
While most individuals who lift weights focus solely on their deltoids when training shoulders, the muscles of the rotator cuff (specifically, the external rotators the infraspinatus and teres minor) are the key players when stability is considered. These stabilizers prevent the humeral head from migrating upward as the deltoids tug on it to raise the arm.
The integrity of the scapula itself is also essential. Unlike the other ball-and-socket joint of the body (the hip, where a complete circuit is formed by three bony components), the five bones that make up the foundation of the upper body (the sternum, two clavicles and two scapulae) are not completely connected. Specifically, the scapulae are not directly attached to one another in the rear so that wide range of movements are possible at the shoulder. But just because bone-to-bone contact is lacking doesnt mean there are no structures to hold the shoulder blades in place. A number of attached muscles are responsible for maintaining their position. And since these muscles are the only units holding this series of bones together, its safe to say they are critical postural players. Every time you move your arm in relation to your shoulder, your scapula moves to reposition the shoulder joint to prevent the head of the humerus from dislocating. Motions of the scapulae include elevation (raising directly upward), upward rotation (raising the outer portion by pivoting), protraction (moving forward toward the rib cage), retraction (drawing back and together), depression (pulling downward), downward rotation (pivoting downward), lateral tilt (angling the bottom part back) and reduction of lateral tilt. Like guide wires, muscles that act on the scapulae are responsible for all of these motions. Stability at the shoulder requires balanced development of all of the muscles that attach to the scapula. That is why typical weight room procedures can create problems. If you dont pay attention to detail, its easy to overdevelop some of these muscles, which leads to imbalances that increase injury potential.
One of the most common deficiencies of scapular alignment involves weak retractors the muscles that function to hold the shoulder blades back. This allows the scapulae to be pulled diagonally, resulting in their inner borders protruding, typically referred to as winged scapulae. Add tight humeral internal rotators (common when chest-building exercises are prioritized) to this mix and youve got a recipe for the typical weightlifters posture rounded shoulders with the palms facing rearward when the arms are hanging at the sides. It is also common for the upper trapezius to be overdeveloped at the expense of the lower traps.
This causes a chronic upward pull on the shoulder blades. Too much emphasis on elevation exercises (shrugs, upright rows and overhead presses, for example) is the culprit responsible for this imbalance. Retraction rows on a cable or vertical row machine are similar to regular rows, with one major modification the upper arms are maintained at slightly below 90 degrees to the body throughout. Scapulae depression can be done from an overhead pulley, with emphasis placed on pulling the shoulder blades down on each rep. This action should also be used to initiate movement on conventional pulldowns for lats. In addition, attention should also be given to keeping the humeral head down during lat pulldowns. Allowing it to be yanked up, on the other hand, increases the potential for the aforementioned impingement.
Fred DiMenna, a Certified Strength and Conditioning Specialist and Lifestyle and Weight Management Consultant, is a two-time Natural Mr. United States and a WNBF drug-free professional bodybuilder. Visit him on the web at www.freddimenna.com or email him at: firstname.lastname@example.org.