Two Joints of the Shoulder
The shoulder is actually two joints in one: the gleno-humeral joint (the ball and socket joint where the upper arm connects to your shoulder blade) and the scapulo-thoracic joint (a functional joint where the shoulder blade slides around on the back ribs). In order to lift your arm up more than about 30 degrees to the side, you have to actually have to move your shoulderblade on your back. (Go ahead: try to lift your arm overhead without moving your shoulder blade – not going to happen).
When we do this motion, the shoulder blades have to protract – that is, they move away from each other and wrap forward on your ribcage (check out the pic). They also they upwardly rotate, which means that the inner border of your shoulder blade actually moves down as the outer edges move up.
“Draw your shoulders down.”
When we’re in yoga class and lifting our arms, we often hear the phrase, “Draw your shoulder blades together” or “draw your shoulder blades down.” These actions are counter-intuitive to the actual bio-mechanics of the shoulder blade on the back. While a small degree of these actions can create stability, too much will restrict your freedom of movement.
When teachers say, “bring your shoulders down,” they are actually trying to get you to relax your upper trapezius. The traps are the muscles at the base of your neck that love to overact and make your shoulders look all crunchy like. While relaxing your traps is a good idea here, we need to remember that part of the shoulder blade must actually be going UP in order to get your arms overhead. Trying to drag the whole shoulder blade down can create constriction and lessen our freedom of movement.
To get freedom in the shoulders as you lift your arms:
- allow your scapulae to move freely on your back body
- externally rotate your upper arms as you bring them overhead to create more space between the bones of your shoulder
- visualize the inner borders of your shoulder blades moving down as the outer borders move up
- relax the muscles at the base of your neck (they’re not needed here) – rather than trying to drag the shoulder blades down your back – to create space around your neck
Some of the muscle that can restrict us when we lift our arms up:
- Latissimus Dorsi
- Posterior Deltoid
Try some dedicated, long stretches for these muscles to open them up. Then explore again and see if one of these has been the culprit.