Update 1/10/22: I wrote this blog post in 2014 (8 years ago at the time of this update!), and It’s really outdated now and doesn’t represent my current approach to yoga, the body, and movement at all. For a more updated, science-based look at the spine in the context of yoga and movement, consider my continuing education course Applied Anatomy for Yogis: The Spine & Core!

Let's take a look today at what we mean when we talk about "backbends" (or "heart-openers, as yogis like to call them :) ), and whether the backbend you're doing is truly a backbend, or if it's something else entirely. Enjoy, and as always, feel free to let me know if you have any comments or questions!

WHAT DOES “OPENING THE HEART” MEAN?

When we backbend, we’re obviously not trying to “open” the literal heart, that vital organ located in our chest that pumps blood through our circulatory system. (That would be bad. :) )

What we’re really aiming to do is to “open” (i.e. “increase the mobility of”) the musculoskeletal area around the heart, which is the rib cage and thoracic spine (mid-back and upper back). And in backbending, we specifically do this by bending the spine backward in the sagittal plane, which in anatomical terms is called spinal extension.

WHY DO WE WANT TO “OPEN OUR HEARTS”?

So glad you asked! The area of our rib cage and thoracic spine is a place that tends to be extremely immobile in most people. Non-optimal breathing patterns, way too much sitting, and less-than-ideal movement habits tend to stiffen our upper- and mid-back over the years. Ideally, we would be able to move the 12 vertebrae of our thoracic spine in relation to one another with ease, but instead our whole rib cage becomes “locked up” and moves more as one big, glommed-together unit.

What happens when one area of our body becomes stiff and immobile? The area just adjacent to it will have to mobilize more to allow your body to move through life and do the things you want it to do. In my hip-opening article, I wrote about how tightness in the hips will cause us to move more than we should from our lumbar spine (low back) area, leading to overuse issues like spinal joint degeneration and herniated discs. In a similar manner, immobility in the thoracic spine will require us to move more from this very same overused lumbar spine area. Poor lumbar spine! This area just can’t seem to get a break. Is it any wonder that by some estimates 80% of us will suffer from low back pain in our lives?

"THE LIFTED CHEST"

This issue is compounded by a postural preference that is imbedded in our culture that you might not even realize is affecting you: it’s the ubiquitous “lift your chest” instruction. From the stereotypical parent telling their slouching child to “sit up straight” to classic military posture, in which the sternum is jutted forward and prominently lifted up; from the aesthetic in our culture that a lifted chest and an arched spine is feminine and attractive in a woman (see the martini glass sexy lady to the right! :) ) to the idea that a man’s protruded chest means that he’s confident and/or strong; the cultural preference for a lifted chest is reinforced endlessly around us.

But is constantly lifting your chest healthy for your spine? If we think about chest-lifting in anatomical terms, what we’re attempting to do is spinal extension - increasing the angle between our vertebrae. (Okay, anatomy nerds, you might say that we’re actually trying to do axial extension instead of spinal extension here, but axial extension is quite a refined movement that most people who “lift their chests” aren’t actually doing, so I’m going to leave that out of the convo for now. :) )

Here’s an oversimplified yoga block art rendition of what spinal extension looks like:

See how the angle between each vertebra has increased a bit, resulting in a chest that lifted, or a spine that backbended? This is a healthy movement for your spine.

SPINAL EXTENSION OR SHEAR?

But we now know that almost everyone’s thoracic spine is immobile and their 12 thoracic vertebrae don’t move much, if at all, in relation to each other. Because of this, if we want to “lift our chests” or do a yoga backbend, our “locked up” thoracic spine and rib cage is actually much more likely to simply shift forward as a whole unit and tilt upward. (Real-life photos below.) Rather than a small amount of healthy extension happening at all 12 vertebral segments, a large amount of unhealthy movement will happen right where the rib cage “sits” on top of the lumbar spine - around the vertebral segment known anatomically as T12/L1. The action that happens at this place is not spinal extension, but is instead something kind of scary-sounding called vertebral shear (with a bit of extension mixed in). The shearing forward of the rib cage relative to the lumbar spine is so common that it’s often referred to as simply rib shear or rib thrust.

(Update February 2016: It's true that the term "vertebral shear" is kind of scary-sounding, but whereas I believed when I first wrote this post that all shear was a non-optimal load for the body, I now believe that there is nothing innately unsafe about shearing loads, and that depending on their intensity and frequency, the tissues of our body are able to adapt to these loads so that they don't pose a safety risk. Any load at a high-enough intensity can certainly be damaging to our tissues, though.)

Here’s an oversimplified yoga block rendition of what vertebral shear looks like. In this example, we’re only seeing shear at one vertebral segment, but with rib shear, it usually happens at a few of the lowest thoracic vertebrae at the same time.

Do you see how one vertebra has shifted forward relative to the one below it? This is not a healthy movement for your spine.

Hanging out with your ribs sheared forward is actually extremely common and just about everyone I know (including all yoga students I see) lives in some degree of rib thrust all of the time. Unless you’re aware of the issue and are consciously working toward re-aligning your body, you are most likely what is affectionately called a “rib-thruster”. :)

Pop quiz: what super-important part of your body is housed within your spine and is the spine's job to protect? Your spinal cord, of course! What do you think happens to your spinal cord when your rib cage shears forward at T12/L1? An unhealthy “kink” is put in it - not to mention the fact that the intervertebral discs below the shear (i.e. your low back) will be compressed and unhappy as well.

WHAT DOES RIB THRUST LOOK LIKE IN A PERSON?

First of all, check out the spinal curves on this nice skeleton here. Can you see that his thoracic spine (the big section of his upper- and mid-back where his ribs attach) has a natural “outward” curve to it which is technically called “kyphotic”? Everyone’s thoracic spine should curve outward like this - our spine has curves for a reason and for optimal spinal function, we need them to be there. (The fact that most people’s thoracic spines have too much outward/kyphotic curve is an issue for a separate blog post, but it is intimately connected to why everyone rib thrusts in the first place.)

Now take a look at these two postures:

In the first photo, I’ve “lifted my chest” (a.k.a. “rib-thrusted”) as per the cultural message (and ubiquitous yoga cue!) that we’re exposed to all of the time. Can you see that my natural kyphotic thoracic curve is nowhere to be seen when I posture my body this way? I’ve hidden it by shearing my rib cage forward and tilting it up. My spinal cord thinks that I am lame in this photo. In the second photo, though, I have nicely let my ribs drop down so that my bottom ribs are nestled into my abdominal flesh. This is where my rib cage belongs. My kyphotic thoracic curve exists again and my spinal cord thinks that I am rad in this photo.

RIB THRUST AND BACKBENDS

Because most of us are already living in some degree of rib thrust (but hopefully this information will inspire you to change this habit, guys!), yogis need to be extra mindful when it comes to backbends. The point of backbends, as we’ve discussed, is to “open” the thoracic spine while performing spinal extension. But do you see how crazily easy it is to bypass opening our thoracic spine completely and to simply rib shear and low back compress in our backbends instead? Most yogis won’t even realize they’re doing this, because the emphasis in yoga is generally placed more on mobility than stability, meaning that we value poses in which someone achieves a great “range of motion” without necessarily considering where that range of motion is coming from and what tissues are creating it.

Here are two photos of me in high lunge (also called “crescent pose”.) Even though high lunge is a standing pose, it is also a backbend because the spine is extending. Or at least the spine should be extending in this pose. But it won’t be extending (at least not optimally) if you do this pose in rib-thrust like most people do. Can you see the difference between my rib-thrusted, spinal compressing high lunge and my nice ribs-down, aligned high lunge?

High lunge is relatively mild as far as backbends go, and it still has the potential to make your spine mad at you. :) But what about some of yoga’s deeper backbends, like urdhva dhanurasana (upward facing bow pose), eka pada raja kapotasana (full pigeon pose), natarajasana (king dancer pose), and kapotasana (from ustrasana/camel pose, arch backwards and grab your feet with your hands)? Or that crazy pose in Ashtanga in which a student in urdhva dhanurasana grabs their ankles with their hands - yikes! While some people do these poses for fun, playfulness, and to strike a pose for Instagram or their yoga photo portfolio which is all fine and good, most people are probably also doing them because they’re supposed to be good for you. But if you aren’t able to stabilize where you are mobile (rib shear) so that you can mobilize where you are too stable (thoracic spine), these poses really won’t offer you anything in terms of positive change in your body and will in fact simply reinforce poor posture habits.

THE GIFT OF BIOMECHANICS

I feel very lucky to have been an active member of the yoga world for 17 years now (!). I have been impressed by poses with great ranges of motion as much as any other yogi and I’ve done all of the “deep” backbends I mentioned above (yes, including walking my hands to my feet in urdhva dhanurasana and holding my ankles - ohmygosh!) But after studying biomechanics and learning more about the science of how the body moves, I have a much different perspective on deep poses like these and what they’re truly offering to our body. As a progressive yoga teacher, my hope is to bring the clarity of this biomechanical perspective to our yoga practice so that we can make informed and empowered decisions about which yoga asanas we decide to do and why.

When Is a Backbend Not a Backbend?