Let's discuss a really common cue that we hear, which a lot of teachers and physical therapists now understand as, at best, an oversimplification and at worst, dangerous.
That cue is “pull the shoulder blades down the back.”
Now, there are moments when this makes perfect sense – essentially anytime the arms are down by the sides. However, when arms are overhead (or really above 90-degrees), it gets a little more complicated.
This is because of how the glenohumeral joint (the ball and socket joint of the shoulder) is put together. Unlike the hips, where there’s a deep socket allowing for lots of stability and weight bearing, the shoulder joint is actually very shallow. You often hear it likened to a golf tee with a golf ball on top.
While this construction allows for a really broad range of motion, it doesn’t provide a lot of stability. This is why we need something called scapulohumeral rhythm. Scapulohumeral rhythm refers to the coordinated movement of the shoulder joint and shoulder blade. Simply put, when the humerus (arm bone) lifts, the scapula (shoulder blade) must also lift to a degree, otherwise, you’re pulling that golf ball away from the tee, which is going to create instability in the shoulder.
Now, I’m not physio, so let's bring this back to yoga. With this understanding, you can imagine what happens when you’re in a position with the arms overhead (like Downward Facing Dog or handstand for example), and a teacher tells you to pull the shoulder blades down the back. You’re putting your shoulders in a dangerous position.
So why does this cue exist?
There’s actually a good reason and meaning behind it, it’s just being poorly described. When teachers tell you to pull the shoulder blades down, what they’re actually referring to is the upwards rotation of the scapula. That basically means that the outside edge of the scapula, near the armpit, is lifting upwards (along with the humerus), while the inside edge near the inner trapezius is slightly sinking downward (to create space in the neck). This is naturally accompanied by shoulder protraction and external rotation.
Perhaps it’s because this rotation is hard to quickly describe, that teachers simply say pull the shoulder blades down. However, if you want to be safe (and accurate), it’s worth taking some time to shift your language to “rotate the shoulder blades”, or “reach the outside of the shoulder blades upwards and gently sink the inside of the shoulder blades down.”
Try it yourself:
Stand in mountain pose, and reach the arms up overhead with external rotation (biceps by the ears and palms facing backwards)
For a moment, elevate the scapula (pull the shoulders up by the ears) as much as possible, just to feel the sensation.
Then, depress the scapula (pull them all the way down). How does this feel?
Return to neutral, then begin to rotate the scapula by reaching upwards with the outside of the shoulder blade, and gently relaxing downwards on the inside by the neck. You should begin to feel a space opening in the neck while the shoulders still feel the sensation of pulling upwards.
Now explore this same sensation in other postures where the arms are overhead such as Downward Facing Dog or Warrior I.
The shoulder is a complex joint that's essential to understand in yoga because of how often we bear weight on it. Before cueing movement in the shoulder, it's worthwhile to functionally understand the movements of the shoulder blade (scapulothoracic joint) as well as those of the glenohumeral joint. Hopefully this can make your cueing more precise and your practice safer.
Have any other great tips for shoulder stability? Share them with us in the comments below!