Rough shoulder ahead?
Posted on Monday, November 26, 2007
There’s something to be said about shoulders. And it’s not that they’re a good place to hang your shirt. Let’s say shoulders are complex. Mobile. Useful. At times, overloaded. They can also be painful, especially when that pesky rotator cuff refuses to rotate. The rotator cuff, a structure of tendons that works with assorted muscles to hold the ball at the top of the upper-arm bone in its socket, could be called the star of the shoulder mechanism. That’s “star” in the sense that most people have at least heard of it or know of someone who has had a rotator cuff injury.
But shoulders are more than rotator cuffs. They carry the heavy load of upper of body mobility and cuff. strength. Shoulders are able to move into 16, 000 positions, according to www. rehabauthority. com, making it possible for us to hit, throw, catch, push, pull, lift and carry. That’s not to say that the rotator cuffs aren’t significant members of the shoulder complex — so termed because of its many components. But rotator cuffs are not islands of movement. The problems that cause those rotator cuff injuries we hear so much about often aren’t confined to the spot where the upper arm meets the shoulder — technically, the glenohumeral joint. Did we say complex ? The shoulder joint consists of three bones: the clavicle, scapula and the humerus, better known as the collarbone, shoulder blade and upper-arm bone. Of the three, it’s the flat, triangular scapula on which much of the shoulder’s health, mobility and stability hinges.
The scapula’s stability comes from the muscles, tendons (cords of tissue attaching muscles to bones ) and ligaments (which connect bones to other bones ) that mobilize it. You might liken the shoulder blades to the platform on a window-washing unit used by the people who clean windows on tall buildings. The platform on its own is rigid like the scapula, but it’s also mobile. And, like the scapula, it’s not stable without help. The windowwashing platform’s stability rests on the tension, flexibility, balance and strength of the ropes and other mechanisms used to operate it.
Cool. But, still, why should we care about the scapula ?
Because the condition of the scapula is related to our ability to function in our daily lives — to do mundane things such as open a door, reach forward to pick up the television remote and lift our arms overhead to pull on a T-shirt.
“The shoulder joint and scapula are inextricably linked — what affects the scapula will affect the shoulder, and vice versa,” Dr. John D. Kelly IV wrote in the July issue of BioMechanics Magazine Online.
Abnormally positioned shoulder blades affect the function of the entire shoulder joint and create an “unstable platform for several muscles,” Kelly says. A common problem is excessive scapular protraction — meaning the shoulder blades are tilted and rotated too far forward.
Visualize the posture of a writer hunched over a keyboard or a teenage gamer in front of his PlayStation and you’ll see the result of excessive scapular protraction.
“The shoulder is going to function best when you have a really good posture,” says Rob Tillman, a physical therapist at Orthopedic Rehabilitation and Specialty Center in Little Rock. “If you sit with a slumped posture, you’re going to have an abnormal position for your scapula or shoulder blade. And that’s going to alter your biomechanics of the main shoulder complex.” Shoulder blades at rest should be retracted, or resting flat, parallel to the spine, Tillman says. But lifestyles today create situations where the opposite, the abnormal, becomes the norm.
Sitting at a desk or in front a computer day after day, year after year, encourages poor posture because the position shortens the pectoral muscles — the bands of muscle across the top of the chest; the ones that body builders develop so that they puff out pillow-like, says Jean-Paul Francoeur, personal trainer and owner of JP Fitness in Little Rock.
Shortened pectorals cause the shoulder blades to move forward and create a strain on other muscles, such as the lower trapezius in the middle back, the rhomboid in the upper back and the levator scapulae (two muscles that angle in an inverted “V” up from the shoulder blades to the top of the neck and connect to the spine ). Also affected is the serratus anterior, a band of small fingerlike muscles under the arm that rotates the shoulder blade outward. When a person slumps all day with his arms in front of him and his hands curved over a keyboard, these muscles are set on constant stretch, Francoeur explains. That stretch leads to weakness.
Even bodybuilders and athletes can experience this type of weakness simply by engaging overmuch in exercises or motions that contract the pectoral muscles — the mirror muscles, as Francoeur describes them because of some people’s propensity for working only on the muscles they can see in the mirror. But no matter how it occurs, constriction of the chest muscles and stretching those in the middle back create a scapular imbalance than can lead to nagging pain, even injury.
The weird thing about such an imbalance, he says, is that it often results in pain in places that seem to have little association with the weak muscle. For instance, the constant stretch of the lower trapezius creates problems throughout the shoulder complex that can show up as a pain in the neck because of pressure on the levator scapulae muscles.
Turn that around and a pain in the neck may indicate a problem with the shoulder complex, says Tillman. For example, slumping creates irritation at the base of the neck. A major nerve at the base of the neck “inervates” or tells a muscle what to do. If that nerve is irritated, it can’t perform its job adequately, which in turn means the shoulder muscle that it inervates can’t function up to par. Therefore, the shoulder’s performance is impaired. And so on and so on.
“It’s not necessarily the chicken or the egg,” Tillman says. But, he notes, “If one thing’s wrong in the region, then the biomechanics are going to be altered in the rest of the region.” Imbalances and weaknesses occur when all the elements — tendons, ligaments, muscles, bone — that are supposed to work together don’t, Francoeur says. They may result in not only aches and pains, but also a lack of “functional strength” that inhibits a person’s ability to perform “random acts of fitness” such as holding a baby against the shoulder while bending down to pick up a dropped set of car keys.
If all that weren’t enough, scapular instability because of biomechanical imbalances puts a strain on... what else ? That’s right, the rotator cuff.
Kelly explains in the BioMechanics article that forwardtilting shoulder blades may change the position of the upper arm bone in its socket so that when you lift an arm overhead, the rotator cuff tendons are irritated.
Over time, the rotator cuff becomes more and more irritated. With enough time and irritation, tears may develop in the tissue. Tears cause pain and make you avoid moving your arm. Lack of movement leads to impingement, which means loss of movement. That creates a need for physical therapy or, in the extreme, surgery. No fun either way.
Francoeur says you can perform some simple tests to check for scapular problems. One involves holding a pencil in your hand (see photos above ) to determine if your shoulder blades tilt or rotate forward while in a resting position. Another requires that you place your hands on your hips and see if the shoulder blades “wing out” or stick out from your body. If they do, “you’re a shoulder injury waiting to happen.” Because muscles involved in the shoulder mechanism feel tight when there’s a problem, a person is naturally inclined to think stretching may help. Not necessarily true, say Tillman and Francoeur, who also say they aren’t referring to light stretching but to aggressive stretching, overstretching.
Tension doesn’t necessarily mean a muscle is tense.
“Weakness disguises itself as tightness,” Francoeur says. If you overstretch a weak muscle, it gets weaker. What it needs is strengthening through specific exercises. (See this page for exercises to strengthen the lower trapezius and serratus muscles. )
Correcting shoulder problems that took years to develop isn’t a simple matter of telling people to sit up straight, Tillman says. Correction takes work and time. And the older a person is, the more time it takes.
So, how can you tell if your shoulder blades are properly positioned ?
Sit. Seen from the side your shoulder should be lined up with your ear, Tillman says. The shoulder blades should be retracted. If they are, “your shoulders are going to be in line with your hips, then you want your head over your base of support.” Support. There’s something to be said about that — healthy shoulders.
Resources for this article include: Biomechanics Magazine Online, www. biomech. com; Inside-Out by Bill Hartman and Mike Robertson; www. rehabauthority. com; the National Institutes of Arthritis and Musculoskeletal and Skin Diseases; National Institutes of Health; Strength Training Anatomy by Frederic Delavier; and www. hesfit. com.
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