PREVENTING INJURIES: Part 4

by Fred Dimenna

One of the benefits of resistance training is improved joint stability, which is critical for injury prevention. But it’s also possible to hurt yourself while you are lifting weights. One of the most injury-prone areas of the body is the shoulder. The shoulder is a complex region that actually consists of four different joints. The one that’s usually considered when we refer to the shoulder is the glenohumeral joint, the articulation formed at the intersection of the glenoid fossa of the scapula (shoulder blade) and the head of the humerus (upper arm bone). This configuration is classified as a ball-and-socket joint, since it consists of the spherical end of one bone rotating in the hollowed-out portion of another. The shoulder shares this structural distinction with the hip joint, but while both are classified similarly, their actual formation is considerably different.

The shoulder is the most freely moving joint in the body. You can move your arm to point up to the sky, down to the floor, out to your side and across your body. You can even rotate your arm at the shoulder like a windmill. (Try moving your leg through that wide a range!) But with this capacity comes a downside. Unlike the hip, where the acetabulum (socket) is deep and provides significant coverage for the rounded head of the femur (thigh bone), the glenoid fossa is shallow and the head of the humerus actually glides around in it as the arm moves. This allows for a wide movement range, but also makes the head susceptible to trauma related dislocations.

Injuries due to this vulnerable configuration are not limited to falls and other impact-associated events, however. Simply holding the humeral head in its socket as the arm performs all of its daily activities is a bit of a challenge. The underlying musculature responsible for this chore (the rotator cuff) is at work constantly, even when your arm is simply hanging down at your side. Compound this chronic use with the fact that the joint is also rather compact and its no wonder this area is frequently injured. With very little room inside to begin with, any inflammation initiates a vicious cycle, whereby injury causes swelling, which in turn creates further injury. It is often difficult to break this cycle and chronic inflammation can eventually progress to torn tissue, a slow-healing malady that can be quite debilitating and sometimes require surgical reparation. Chronic stress to the shoulder is also exacerbated when postural alignment is flawed. A typical structural defect, like the round shouldered posture associated with weak scapulae retractors and tight humeral internal rotators, can interfere with motion at the shoulder. Many individuals who lift weights to improve their physical being wind up with this imbalance, which can be identified by observing where the palms face when the arms are hanging freely at the sides. The arms should face the legs; the palms not rear-ward. This misalignment impinges upon the aforementioned musculature even more. This disadvantageous biomechanical alignment forces the muscles to work harder, further increasing the likelihood of chronic overuse.

Since the opening between the bony acromial arch and the underlying musculature is maximally reduced when the arm is raised overhead, all exercises that necessitate this posture should be avoided when attempting to train around a shoulder injury. Barbell presses done behind the neck are particularly problematic. Since lowering the bar without hitting the head in this case necessitates considerable external rotation of the humerus, the limited space available is compressed further. Pulldowns where the bar is passed behind the head also necessitate assuming this vulnerable position although, in this case, the fact that the load is pulling up, not pushing down, reduces some of the danger.

A thorough shoulder workout can still be performed without raising your arms above parallel to the ground. Dumbbell raises done to the sides, front and rear are effective exercises for strengthening the superficial muscles of the shoulder (the deltoids) without creating the potential for impingement. The rotator cuff musculature can also be strengthened to prevent the likelihood of recurrence. Rotating the arm inward and outward against resistance emphasizes three of the four muscles that make up this group (the subscapularis and the teres minor and infraspinatus, respectively). The fourth (the supraspinatus) can be stressed by modifying your lateral raise technique (an exercise known as scaptions). This involves turning your hands so your pinkies face upward and raising the dumbbells diagonally, halfway between your front and side. Rotator cuff exercises are important, but beware: They won’t heal a pre-existing injury. In fact, they could potentially exacerbate the overuse. So, the key is prevention. Use these exercises judiciously when your shoulders are healthy to avoid problems in the future.

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: mrnaturalus@yahoo.com.