Each time you lift your arms, your shoulder muscles (big and small), initiate a flowing movement of subtle nuances. Because of the complex interaction of those muscles, coupled with the unique structure of the shoulder joint, gives our arms a wide range of motion. You might want to keep awareness that, the shoulder is one of the loosest joints in the body.
That flowing freedom increases the vulnerability of the shoulders to injury; both from sudden falls and from repetitive action such as playing golf or simply throwing a baseball. The muscles of the rotator cuff, the most delicate movers of the shoulders, are particularly susceptible.
However, a regular targeted asana practice can help you maintain healthy rotator cuffs by bringing awareness to your alignment, strengthening your shoulders muscles, and opening your chest.
Let’s take a look at the special nature of the shoulder joint and, in particular, its relationship to the shoulder blade.
Though it is considered a type of ball-and-socket joint, the shoulder is unusual because the rounded “ball” or head of the humerus (i.e., the arm bone) doesn’t have a corresponding socket.
Rather, the ends of the collarbone and shoulder blade come together to form a shelf under which the humerus hangs.
This shelf is know as the acromion process.
Beneath it there is rounded depression that is part of the shoulder blade.
This is as close as the shoulder gets to having a “socket”; the head of the arm bone glides against this surface as it rotates, and the steady contraction of the rotator cuff helps to hold together.
The rotator cuff actually comprises four separate muscles-the supraspinatus, the infraspinatus, the teres minor, and the subscapularis-which wrap over, in front of, and behind the head of the humerus and stabilize the joint. These deeper muscles are layered over by larger, stronger muscles that attach directly to the acromion process.
The muscles of the rotator cuff guide the actions of the arm bone itself, while other larger muscles control the actions of the shoulder as a whole, with both arm bone and shoulder blade functioning as a unit.
How Injuries Occur
The most common rotator cuff injury occurs at the outermost corner of the shoulder, beneath the deltoid (the large muscle you use to lift your arm). The injury is to the supraspinatus, a small muscle that attaches directly to the head of the humerus and assists the deltoid in lifting the arm overhead. The very strength of the deltoid is often the cause of injury to the supraspinatus.
When you take your arms overhead, the deltoid is able to raise the arm to 80 degrees from the body. At this point, the deltoid can’t do much more lifting on its own: the arm bone is almost level with the shoulder, and from this angle the deltoid can only pull the arm bone into the joint rather than lift it higher.
As the arm continues to rise, the deltoid relaxes somewhat and the supraspinatus jumps in to help: it raises the arm for the next 30 to 40 degrees, after which the deltoid can resume its work.
It is within this range of 80 to 120 degrees that the supraspinatus can get hurt. The tendon of the supraspinatus, which is about the size of a large rubber band, is the part of the muscle most often injured, though the muscle itself can also tear.
This could happen in aggressive (downward facing dog) poses, as well as (side plank pose), and in advanced arm balances such as firefly pose.
Simple accidents can also injure the supraspinatus tendon.
For example, if you slip in an icy parking lot and use your arm to break the fall, the humerus gets jammed in the socket, pinching the supraspinatus against the acromion process or even tearing the tendon.
The simple repetitive action or raising your arm can also be at fault.
When you reach for something on a shelf above you, the deltoid can pull the arm bone up too hard, pressing it against the acromion process, thus punching the supraspinatus. Over time, these little injuries add up to a more serious problem.
The shoulder is built to avoid this pinching, but our patterns of use and everyday life leas to imbalance, pain, or lack of mobility. The problem starts with postural habits: many of us overuse the muscles of the shoulders to support the weight of our arms. The muscles closest to the neck (the rhomboids) and those running from the top of the shoulder blades up into the neck itself (the levator scapulae) take the brunt of the weight. This is especially problematic during arm-intensive activities such as typing, when your shoulders become set in a perpetual shrug. Chronic tension builds up, pulling the inner corners of your shoulder blades up toward your ears, causing your back to round and your shoulders to hunch.
This is the beginning of a vicious cycle; the more your shoulder blades creep up the back from the pull of these muscles, the more your muscles tense and shorten, pulling your shoulder blades up even higher. As a result of this tension and the postural misalignment that ensues, the deltoid is far less likely to relax when it’s supposed to. If your shoulders roll forward and the deltoid remains fully engaged as you lift the arm from 80 to 120 degrees, it can cause the humerus to press against the acromion process, pinching the rotator cuff tendon.
There are a variety of poses that can help break the cycle and restore strength and balance to the shoulder muscles-from simple standing poses in which you hold your arms a loft in various positions to those in which your arms directly support the weight of the body. Standing poses can help you reestablish the healthy mobility of the shoulder blades as you lift your arms; they will also enable you to activate other muscles to ease the burden on the rhomboids and levator scapulae.
The inversions, particularly the headstand, strengthen the shoulder muscles, keeping them more open and stress-free.
Last but not least;
“Allow yoga to wash the weight of the world from your shoulders.”
Glenda Lee Santos; Humble Military and Yoga Warrior; Criminal Justice, BA; RYT-200 hrs; Holistic Practitioner with Foundation in Yoga and Ayurveda; Reiki Master; Spirit Guide Coach; Master Resilience Trainer.