Update 1/10/22: I wrote this article in 2015 (7 years ago at the time of this update!) and I’ve learned much more about the human body, movement science, and the shoulders specifically. Some of what I wrote in this article is outdated now and doesn’t reflect my current approach.

For a more updated, science-based perspective on the shoulders, consider my continuing education course: Applied Anatomy for Yogis: The Shoulder!

One of the most common instructions we tend to hear in yoga class is “pull your shoulders back”. This cue is often offered as a universal guideline for how we should position our shoulders throughout our entire practice, and it has its roots in a broader cultural idea that “shoulders back” is inherently good posture. In fact, this belief is so ubiquitous that we often don’t think to question the anatomical reasoning behind it. But as we now know, many of yoga’s traditional alignment rules could benefit from the insight of a more modern movement-science perspective. It turns out that as well-intentioned as the “shoulders back” cue is, on an anatomical level this instruction does not solve postural issues, nor does it help our body function better.

THE ANATOMY OF “SHOULDERS BACK”

For many of us, the extent of our anatomy knowledge is that our shoulders are the general, vague area located underneath the prominent shoulder pads of our mom’s awesome 80’s blazer. :)

This seemingly-simple part of the body is quite complex, however, consisting of three separate interlocking bones and four individual moving joints. At the bony level, our shoulder (often referred to anatomically as the “shoulder joint complex” or the “shoulder girdle”) actually looks something more like this under those eye-catching shoulder pads:

The shoulder girdle can move in a myriad of different ways. One pertinent pair of shoulder movements for our discussion today is protraction and retraction. When we protract our shoulders, our scapulae (shoulder blades) move away from one another on our back, and when we retract, they move toward each other. One of today’s postural realities is that many of our yoga students present with “rounded-forward shoulders” and the corresponding appearance of a caved-in chest. We interpret this overly-protracted position as non-optimal, and we therefore naturally conclude that in order to remedy it, our students should pull their shoulders back, or retract their scapulae, throughout their entire yoga practice.

But this well-intentioned notion is problematic for a few reasons. The first and possibly most fascinating has to do with a lack of awareness that many of us have about the way we move. Unless we’ve consciously worked to change this pattern, most of us aren’t actually able to pull our shoulders back without also moving our spine into a slight backbend. In anatomical language, we would say that most people aren’t able to retract their scapulae without also extending their spine.

Just to make sure we understand the clear difference between these two movements, let’s take a look at a simple visual aid. Scapular retraction is a horizontal motion performed by the muscles that lie between the shoulder blades and the spine:

Whereas spinal extension is a vertical movement performed by the muscles that run up and down along the spine, like this:

Although these are clearly two distinct anatomical actions, in most people they have become “lumped together” as one undiscriminated movement. Therefore, when we ask students to pull their shoulders back, they will more than likely also unconsciously extend their spine.

Now spinal extension is of course a fine movement in general, but if we’re asking our students to move their shoulders back, we’re really requesting pure scapular retraction - no unnecessary extra movements included. Aside from that, as I’ve discussed before, when many of us extend our spines, we end up unknowingly performing most of the movement at T12/L1, the very mobile vertebral segment at which the thoracic and lumbar spines meet. When this happens, our front lower ribs protrude forward, our chest lifts toward the sky, and we end up creating non-optimal compression in the lumbar spine region. This is not a favorable position for our spine, but it is the position that 95% of our students will assume if we ask them to pull their shoulders back.

Another reason that constantly pulling our shoulders back all day is undesirable is that it negatively impacts the quality of our breath. The “shoulders back, chest up” position which we so commonly equate with good posture in fact impedes our ability to take a full, nourishing breath. Give this experiment a quick try in your own body: for a moment, pretend that your yoga teacher just cued your class to pull their shoulders back, and be a dutiful student by retracting your scapulae and lifting your chest. Then place your hands on either side of your rib cage and take a full breath cycle of inhale and exhale, allowing your rib cage to swell laterally into your hands on the inhale. Notice how deeply you were able to inhale. Now stop squeezing your scapulae back - just allow your shoulders to relax forward - and find a neutral rib cage by dropping your front low ribs down until they are buried beneath your abdominal flesh. Try inhaling into your hands in this new position. Your breath capacity should be noticeably more expansive. This is a perfect example of how the way you choose to position your body in space can have a direct effect on how your body functions.

A third reason that chronic scapular retraction is problematic is that this action creates unnecessary tension in our upper- and mid-back. In fact, if you happen to be familiar with massage therapy, you might know that the rhomboids and middle trapezius - the muscles that lie in between the shoulder blades - are a classic place in which clients love to receive massage. One main reason that this area so commonly craves the therapeutic touch of massage is that many of us spend the majority of our day using muscular effort to pull our shoulders back. Massage helps to relieve the chronic tension created by this habit, but its effects are usually only temporary.

WHAT SHOULD WE DO WITH OUR SHOULDERS INSTEAD?

As radical as it might seem, instead of pulling your shoulders back, try simply allowing them to relax. Let go of any retracting effort and just let your shoulders naturally fall where they will. Although this might “feel” to you like your shoulders are too rounded forward, the truth for most people is that if they were look at themselves in a mirror, they would discover that their shoulders are not nearly as far forward as they thought they were (although some rounding is quite normal). Allow your default alignment to be a shoulder girdle that is relaxed and free from effort. And then in the longer term, begin to proactively target the tension that is pulling your shoulders forward in the first place with smart stretches and conscious movement exercises designed for the pectoralis major and pectoralis minor muscles of the front of the chest.

In conclusion, the idea that we should pull our shoulders back throughout our whole yoga practice (and all day long in general) is a universal alignment cue that does not serve our body well. Let’s instead learn to only offer this cue during yoga asanas in which scapular retraction enhances the specific anatomical purpose of the pose. The more that we strive to teach intentional movement versus scripted alignment cues, the more our students will benefit from the insightful quality of our classes!
 

Related:

Continuing ed course: Applied Anatomy for Yogis: The Shoulder!