5 Things We Didn't Learn About the SI Joint in Yoga Teacher Training

Today I'd like to offer 5 insights about the SI joint (or sacroiliac joint) that we don't tend to learn about in yoga teacher training, but which definitely have implications for how we teach and practice yoga. Also included are multiple scientific references for each point. I invite you to read these points with an open mind and a willingness to possibly question your own biases (because I know I have had to question my own many times as I continue to study and learn about the body!)

 

 

Insight #1: The SI joint is a strong, resilient structure that is supported by thick layers of some of the strongest ligaments and muscles in the body. [Ref, Ref, Ref]


Although the SI joints are some of the strongest joints in the body, we often receive the impression from our yoga teacher trainings that they are actually quite fragile structures that are vulnerable to injury and instability from the slightest misalignments in yoga. For example, we are sometimes taught that if we hold our pelvis "square" when we twist in poses like twisting triangle (parivrtta trikonasana), we can "tweak" our SI joints by pulling them out of alignment, and we should therefore instead always be mindful to let our pelvis turn slightly in the direction we are twisting in these poses. Another example is that we are often instructed in backbends like bridge pose (setu bandha sarvangasana) and locust pose (shalabhasana) to relax our glutes (or to at least soften them somewhat) because if we contract them too hard, this could injure our SI joints.

One reason we tend to believe that our SI joints are vulnerable to damage in yoga is that we generally learn about SI joint anatomy by looking at a skeleton model or a drawing like this one here:

 
 

When we see the bones by themselves like this, we can certainly get the impression that the sacrum can "slide around" relative to the pelvis easily, resulting in an SI joint that can be pulled "out of place" or "strained" due to small misalignments in yoga poses.

However, what we rarely see after learning about the bony anatomy of the SI joint's structure is an image like this, which depicts all of the extremely resilient, tough ligaments that surround and support the SI joints from all sides, holding them firmly in place:

The ligaments that support the SI joint include the anterior sacroiliac ligament, interosseus sacroiliac ligament, sacrotuberous ligament, posterior sacroiliac ligament, and sacrospinous ligament.

The ligaments that support the SI joint include the anterior sacroiliac ligament, interosseus sacroiliac ligament, sacrotuberous ligament, posterior sacroiliac ligament, and sacrospinous ligament.

 

A rarely-cited fact is that the ligaments of the SI joint include some of the strongest ligaments in the human body! [Ref]

If after seeing an image of the SI joint's ligamentous support, we were then shown an image like this one below, which depicts all of the thick musculature and fascia on top of all of those ligaments on top of the SI joints (including the powerful gluteus maximus, the largest muscle in the human body), we might have reason to be more confident and less fearful about this naturally strong, sturdy area of our body:

 
 

 

While our SI joint can certainly be injured and we can absolutely experience pain there (more on this in #4), it would take much more force to injure a healthy SI joint than the relatively low loads involved in a yoga practice.

 

Insight # 2: The SI joints are inherently stable by design, not inherently vulnerable. [RefRef, Ref]

The SI joints serve to transfer the load of the upper body to the lower body, as well as to distribute forces moving up the body from below. Therefore, stability is built into their very design so that these forces can be transferred efficiently through the pelvis.

In fact, the SI joints are so inherently stable that there is only the tiniest amount of movement available at these joints. While some sources state that the amount of motion available at the SI joint is a barely-perceptible 2-4 millimeters, other sources actually state that there is in fact no movement available at these joints at all.

 

Insight #3: Even if the SI joints could "slip out of place" easily, we don't have a reliable way to assess this in someone's body. [Ref, RefRef, Ref, Ref]

SI joint movement is so minute and difficult to identify with either manual palpation or radiographic imaging that none of the tests traditionally done to assess the SI joint have been shown to be reliable. Without an accurate method for testing the position and movement of an SI joint, how can we definitively know that someone's SI joint is "out of place", "misaligned", or "unstable" in the first place?

 

Insight #4: SI joint pain is certainly a common experience among yogis and non-yogis alike, but SI joint pain does not necessarily mean that there is an SI joint injury. [Ref]

His left hand would actually be a bit lower if this were truly SI joint pain. (I couldn't find a photo that showed the right spot - they all seem to feature general low back pain instead!)

His left hand would actually be a bit lower if this were truly SI joint pain. (I couldn't find a photo that showed the right spot - they all seem to feature general low back pain instead!)

Thankfully, insights from modern pain science are beginning to become more widely known in the yoga world, but if this topic is new to you, consider taking a look at the introduction to pain science article that I wrote for Yoga International a couple of years ago. It turns out that despite what we have traditionally been taught, pain and tissue damage often do not correlate on a 1:1 basis - especially when pain is experienced in a more persistent or chronic way. Pain is actually a much more complex, multi-factorial phenomenon than simply "I have tissue damage and therefore that is what is creating my pain."

As an example, if someone has SI joint pain and they have experienced a recent blunt force trauma to their pelvis region (think from a car accident or a major fall of some sort), then their pain is very likely due to an actual SI joint injury. Once this injury has healed, this pain should subside. In fact, my husband and I suspect that his SI joint may have been injured many years ago in yoga by a strong adjustment he received. His yoga teacher forcefully pulled both of his legs behind his head in a pose called dwipada sirsasana and he felt a searing pain at his left SI joint in that moment. Thankfully the injury healed, but this type of forceful, deep adjustment seems like it was enough to cause injury to his SI joint (or at least a strong protective output of pain in the area).

But in contrast to those examples of short-term pain associated with acute injury, when someone's SI joint pain is more long-term or chronic in nature (chronic pain is sometimes defined as pain lasting longer than 3 months), it's less likely that this pain is connected to a specific injury or damage to the area, and more likely that the person's nervous system is instead sensitive around that spot. Nervous system sensitivity and an output of pain can be the result of many different factors aside from actual tissue damage. Other influences include emotions, past experiences, stress levels, beliefs - and particularly beliefs about one's body. In fact, the more that someone believes that their SI joints are fragile and vulnerable, the more likely their nervous system is to perceive threat in that area and to output pain there. And conversely, the more someone learns that their SI joints are strong, inherently stable structures well-supported by some of the most durable ligaments and muscles of the body, the less likely their nervous system will be to perceive threat and output pain in this area. [Ref, Ref]

 

Insight #5: Warnings about protecting the SI joint in yoga are often unnecessary.

As we have seen, the SI joints are held stable by a ligamentous and musculature support structure that is strong and resilient - and the joints themselves have only a tiny amount of movement available (if any) in the first place. With this in mind, whether or not we hold our pelvis square when we twist in yoga is probably not a likely mechanism for SI joint injury either way, given the relatively low loads involved in the pose. And whether or not we squeeze our glutes in backbends in yoga is also unlikely to be a mechanism for SI joint injury; in fact, contrary to the common cautions in yoga, contracting our glutes in backbends has actually been shown to have a positive stabilizing effect on the SI joints. [Ref, Ref]

Additionally, it's common these days to hear warnings about "overstretching" the ligaments of the SI joints in yoga poses, leading to SI joint instability and pain. (I myself used to offer such cautions too - the idea just seems to make sense!) We are learning, however, that this is not actually how ligaments respond to stretching. During a stretch, a ligament lengthens temporarily, but then it returns to its resting length afterward (sometimes after a short recovery period.) Despite popular warnings, passive stretching has not been shown to lengthen and destabilize ligaments and joints. I have personally changed my perspective on this issue due to insights from newer research and teachings from my yoga biomechanics mentor Jules Mitchell.

(For more reading on the fascinating topic of stretching, ligaments, and joint instability with lots of research references cited, I encourage you to read this recent blog post by Greg Lehman, a researcher and clinician whose work I have followed and admired for quite some time now. But fair warning: this post is long and is really territory for the more serious body geeks among us. You can always jump right to "Questionable Assertion #3", which specifically addresses these topics and might offer some new, interesting information for you to ponder.)

 

IN CONCLUSION...

In summary, SI joint pain is common among yogis and non-yogis alike and there are many factors that can contribute to it, including physical, psychological, and social ones. How we align our body in yoga is probably not a mechanism for SI joint injury, though (strong, forceful adjustments by yoga teachers excepted!) Rather than worrying too much about alignment for SI joint protection, a more effective means to injury-prevention is to simply strengthen and condition the muscles and connective tissue that support the SI joint, so that their capacity to handle load increases.

Thank you for reading these 5 points with an open mind, and I hope to see you on the mat virtually or in person in the near future!

[Microblog] There is No "Right Way" To Do A Yoga Pose

hovering-pigeon.jpg

When I think about yoga alignment, the approach I take these days is that there is no one "right" way to practice any yoga pose. The right way to align a yoga pose really depends on who is practicing the pose and what their individual goals are. Our goals can also change every time we practice a pose, and that's actually great. Otherwise we just practice the same thing the same way all the time and never provide new input into our tissues or our nervous system.

In this "hovering" variation of pigeon pose, my goal is to create *strength* in my hips in a pigeon-like joint arrangement. This is good stuff that will create tissue health and neurological control in my hips - something that nearly all of us can use more of. Consider changing up your pigeon pose regularly and all your other poses too - as long as they align with your specific goal in the moment, then that is "right" way for you to practice the pose.

Top 5 Movement Science Insights For Yoga Teachers

These are 5 of the most eye-opening insights I have learned from anatomy, physiology, kinesiology, and pain science that have given me a much different perspective on the body than the one I learned through my yoga studies alone. I hope you find these ideas interesting and inspiring for your own yoga practice and teaching!

Each of these insights is simply my best offer at a summary and takeaway for yoga teachers who might not have the time or interest to study these issues thoroughly on their own. There are volumes more to be read about each of these points from primary and secondary sources, so feel free to investigate the links and references I've included below, or to do your own research on these topics to help you come to your own conclusions.

If you're interested in how one might embody these Top 5 insights in their yoga teaching, consider trying some classes in my online class library, which is a great resource of practices from myself and other wonderful science-minded yoga teachers I admire.

Please read the insights below with a willingness to question your own biases and an openness to incorporate critical thinking into your approach to yoga and movement. Without further ado, here are my Top 5 Movement Science Insights For Yoga Teachers!

 

 

MOVEMENT SCIENCE INSIGHT #1: STRETCHING & STRENGTHENING ARE NOT OPPOSITES

One of the core rules we tend to learn in our yoga teacher trainings is that after we've "worked" or “strengthened” a muscle or muscle group, we should then stretch the area to lengthen it back out and restore "balance". The reasoning behind this rule is usually that when a muscle "works" or "contracts", it is shortening. Therefore to avoid leaving your muscle in an excessively shortened state, you should balance it out by "lengthening" or "stretching" it after you've worked it.

This idea would make sense if muscles did only shorten when they contract. But shortening while contracting is actually only one part of the physiological equation - muscles work just as often as they lengthen too. Picture your hamstrings and the way they lengthen while they're working to control your swan dive into uttanasana (standing forward fold) in yoga. When a muscle works as it lengthens, this is called an "eccentric contraction", and we move this way all the time in our normal human movements. [Ref]

Because muscles can and do actually contract through all of their ranges (short, long, somewhere in between, etc.), it is clear that the physiological opposite of a muscle contraction is not a stretch. With this in mind, it might be time to re-think our classic "strengthen it, then stretch it" rule!

 

MOVEMENT SCIENCE INSIGHT #2: NO YOGA POSES ARE INHERENTLY "BAD" OR "GOOD"

Last year I wrote a blog post called Are Some Movements Inherently Bad? which basically suggested that no movements are inherently “bad”, and the only truly bad movement is one for which your individual body is not prepared or conditioned. But the inverse of this insight is also true. While no movement is inherently bad, no movement is inherently good, either. There is a trend in the yoga world toward teaching yoga poses and other movements like “corrective exercises” that are thought of as "better", more "functional", or "healthier" for the body. But the reality is that movements don't have inherent value (i.e. "better for you", "worse for you", etc.) outside of the specific context of who is practicing the movement and with what goal in mind.

We honor the complexity of the human body and its relationship to movement when we avoid valuing certain yoga poses and movements as inherently better, more functional, or worse than other yoga poses and movements. Context and individualized goals are the main determinants of what makes a movement “good”, “bad”, “functional”, or “dysfunctional”.

 

MOVEMENT SCIENCE INSIGHT #3: ALIGNMENT IS LESS ABOUT INJURY-PREVENTION AND MORE ABOUT LOAD-OPTIMIZATION

We generally learn in our yoga teacher trainings that alignment is important in yoga poses primarily because it prevents injuries. However, we’re now learning that the categories of alignment, injury, and pain are not as interrelated as we have previously been taught. Many people exhibit “poor alignment” and are pain-free, while many others exhibit “stellar” alignment and have chronic pain (and to make matters more confusing, pain and injury (i.e. tissue damage) are also not always correlated either.) [Link]

It turns out that the human body is more resilient and adaptable than previous models of alignment and pain have accounted for. Our body actually has a remarkable ability to adapt to become stronger in response to the loads it experiences (as long as those loads aren’t beyond the ability of our tissues to withstand.) [Link] Therefore if we habitually position ourselves in a way that is different from “ideal alignment”, it’s less likely that our body will sustain inevitable damage from the “misalignment” and more likely that our body will simply adapt to better handle the loads of this alignment. (This is assuming that the joints in question are asymptomatic and healthy, of course!)

Now in a high-load situation, such as squatting in the gym with a 300-pound barbell on one’s back, alignment is undeniably an important tool for minimizing risk of injury. [Link] Activities like this involve high forces that are more likely to be beyond the ability of our tissues to withstand, and so aligning our joints intelligently is definitely recommended.

But compared to heavy weightlifting scenarios, yoga is for the most part a low-load activity. Small variances in alignment under low load are not enough to cause inevitable injury and damage in most bodies. For example, if someone’s front knee drifts inward a few centimeters in warrior 2 (breaking the classic alignment rule of keeping the knee stacked directly over the ankle), the tissues of the knee will most likely respond to that load by adapting to become stronger at that angle. And if the shoulders drift slightly out of “joint-stacked” alignment over the wrists in plank pose, the shoulders, elbows, and wrists should be signaled to grow stronger and better able to handle load from this new angle.

In fact, exposing our body to variable loads like this is actually a great way to prevent injury because it helps condition our tissues to become stronger at all angles, rather than strong in only the classic “joint-stacked” position of traditional alignment rules. I would argue that increasing the ability of one's tissues to tolerate load by strengthening the body at all angles and ranges is a much more effective strategy for injury-prevention than "alignment" is.

These days I view alignment as a tool that helps my students direct the loads in their bodies where I intend for those loads to go, rather than as a necessary tool for injury-prevention.

 

MOVEMENT SCIENCE INSIGHT #4: WE USE TOO MUCH FEAR-BASED LANGUAGE AROUND ALIGNMENT IN YOGA

This insight piggybacks right onto insight #3. It’s very common in the yoga world to pepper our alignment instructions with cautionary language, such as “Align your front knee right over your ankle in Warrior 2 to protect your knee” or “Press your pubic bone into the floor in shalabhasana to keep your low back safe.”

As well-intentioned as they are, warnings like this can actually serve to instill a false sense of fragility in our students, which can counterintuitively result in their experiencing pain. We know now that pain is a creation of the nervous system in response to a perceived threat. And our beliefs about our body are actually one influence that can directly escalate or de-escalate our nervous system’s perception of threat and output of pain. [Ref], [Ref], [Ref] Therefore the more we trust in the robustness and resiliency of our body, the more we communicate a message of confidence to our nervous system, which is likely to result in lower threat levels and decreased pain. And conversely, the more we believe that our bodies are innately fragile and vulnerable to injury from low loads and small micro-“misalignments”, the more likely our beliefs are to contribute to increased threat levels and increased pain.

In warrior 2 pose, stating that keeping the knee directly above the ankle is important “to protect your knee” is a potentially nocebic suggestion to offer to our students. (A nocebo is a negative expectation of an otherwise harmless event or action that causes negative consequences like pain.) Likewise, stating that the pubic bone should stay grounded in shalabhasana “to keep your low back safe” suggests to our students that their spines are fragile structures that will experience damage if their pelvis is tilted a few millimeters in the “wrong” direction.

Instead of using cautionary, nocebic language about alignment in our yoga classes, consider talking about alignment in terms of what it helps us achieve in our poses. For example, in warrior 2 we could say “Keep your front knee lined up over your ankle to engage your lateral hip muscles” or “Press your pubic bone into the floor in shalabhasana to lengthen your low back and direct the backbend into your thoracic spine.” These types of cues utilize alignment more for load-optimization reasons and less for injury-prevention reasons. Instead of instilling a sense of fragility about their bodies, these types of cues encourage increased body awareness in our students, which can be confidence-building and empowering.

 

MOVEMENT SCIENCE INSIGHT #5: TWO COMMON YOGA CUES WE CAN STOP USING

We often teach yoga poses in a way that tells our students which specific muscles they should (or should not) be contracting in particular movements.

In certain contexts, suggesting which muscles a student should be using at any given time can be a useful type of guidance. But it's helpful to realize that as a general rule, our nervous system actually does a good job of automatically organizing and coordinating the movement of our body all on its own, without needing much conscious input from our thinking mind. In fact, consciously "micromanaging" which muscles our nervous system chooses to recruit can often interfere with our built-in, sophisticated motor control system in a way that results in less efficient movement. [Ref]

With this in mind, here are two cues that are very common in the yoga world today that we could all use to stop giving:

1) The glutes & bridge/wheel: there is no need to tell our students that they should "soften their glutes", "relax their glutes", or otherwise disempower the main muscles of hip extension that their bodies naturally recruit when they lift their hips up into bridge pose (setu bandha sarvangasana) and upward-facing bow pose (urdhva dhanurasana). [Ref]

2) Arms overhead & shoulder positioning: there is no need to cue our students to "pull your shoulders down your back" when their arms are overhead. When our arms lift up, our shoulder blades naturally rotate and lift along with the arm movement. [Ref] This is a normal, optimal movement that is often referred to as "scapulohumeral rhythm", and it is not helpful to interfere with this natural coordinated action by trying to consciously pull the shoulder blades down the back to prevent them from lifting.

 

Thank you for reading these Top 5 insights with an open mind, and I hope to see you on the mat virtually or in person in the near future!

Are Some Movements Inherently Bad?

We are often taught that there are ways the body can move that are inherently bad for us. We’re told that these movements will cause damage, “wear and tear”, or imbalance in the body, which will inevitably lead to pain and discomfort. Some examples of movements like these are cervical spine flexion (e.g. "text neck"), lumbar spine flexion, and many classic yoga alignment taboos like placing the foot directly on the knee in tree pose (vrksasana).

While this perspective is certainly well-meaning, it is missing some key insights about the body that recent science has revealed to us. Instead of asking whether a movement is good or bad, a more nuanced and helpful question is: are one’s tissues adapted to withstand the load of a particular movement? When we approach movement from this perspective, it becomes clear that there are no inherently bad movements - there are simply movements whose loads our bodies are not currently adapted to handle.

 


OUTDATED MODEL OF PAIN

One reason that the "bad movements" belief is unhelpful is that it is based on an outdated model of how pain works. If you read my recent article on The New Science of Pain in Yoga International, you may be familiar with the fact that the link between pain and actual tissue damage is often very weak. Recent studies have repeatedly shown that many people have real tissue damage in their bodies and no associated pain, and conversely, many people who experience chronic pain in their bodies have no associated tissue damage at all. Additionally, pain is not an input to the brain from the periphery of the body (i.e. from tissue damage), but an output from the brain that is meant to signal us to take some sort of protective action.

There are many more implications that the new science of pain has for today’s topic of “bad movements”, but for the sake of time I’m going to to leave this part of the discussion at that and encourage you to read my original article about pain if these ideas are new to you. (This paradigm shift is fascinating and important for us yoga and movement teachers to understand!)

 


DO OUR PARTS WEAR OUT LIKE THE TIRES ON A CAR?

The second main issue with the “bad movement” approach is that it is based on a model that views the body as similar to a car, or a machine. In this model, if we move or align our body in sub-optimal ways over time, certain body parts will wear out before others due to the accumulation of microdamage. Just like a car’s tires might wear out unevenly and need premature replacing if they aren’t aligned properly, our body’s joints (think knees, hips, spinal joints) can wear out if we move or align them poorly.

This idea makes great intuitive sense, but there is an important distinction between cars and human bodies that is missing from this perspective. Unlike a car or a machine, whose parts do mechanically wear out with time, our body consists of living, biological tissues which are constantly turning over and remodeling according to the demands they experience. For example, we all know that if we load our muscles and connective tissues with a weight-training program at the gym, they will respond by becoming stronger in order to handle these loads. Another way of saying this is that the tissues of our body adapt to the stresses placed on them (also known as Davis’ Law).


TEXT-NECK AND TISSUE ADAPTATION

Text-neck is not an inherently damaging movement.

Text-neck is not an inherently damaging movement.

As counterintuitive as it may seem, this same principle of adaptation applies in the case of the traditionally-labelled bad movement of “text-neck”. We are often cautioned that our head weighs the approximate amount of a bowling ball, and for every inch forward that it creeps, our neck is burdened with 10 additional pounds of damaging weight, leading to inevitable pain and imbalance in this area. (I have warned my yoga students about the dangers of text neck myself in the past too - believe me!)

But such cautions are rooted in the model which views our body like a machine full of parts that will wear out and break down if poorly aligned. By contrast, the living, biological organism of our body is constantly adapting to the loads it experiences. Therefore, if you position your head slightly forward of your torso on a regular basis, the muscles, fascia, and connective tissue of your neck will naturally adapt to become stronger and better able to withstand this load.

Now it’s certainly the case that holding any position for a long period of time, be it text-neck or otherwise, is problematic. But simply flexing our neck forward to look down is a natural movement that our body is designed to do. As well-intentioned as the cautions against text-neck are, they are not truly science-based and can encourage unnecessary fear and worry around this movement (which, ironically, can contribute to pain!)

 


“BAD ALIGNMENT” IN TREE POSE

Yoga alignment rules are another realm where "bad movement" beliefs often come into play. One classic example is the instruction that nearly every yoga student has heard to never place the foot on the opposite knee in tree pose (vrksasana). The reasoning behind this alignment rule is that the laterally-oriented force that the foot applies can damage the knee joint. We are instead instructed to always place our foot either above the knee (on the thigh) or below the knee (on the shin).

This alignment taboo does make intuitive sense, but let’s use the lens of biomechanics to look a bit closer. First of all, as we discussed above, the tissues of the body adapt to the loads placed on them. Therefore, in theory, if someone were to practice tree pose with their foot on their knee frequently enough, the tissues of the knee should adapt and get stronger to handle that load.

Secondly, yoga teachers often cue their students to actively press the standing leg and tree leg foot into one another in this pose. If practiced this way, this action actually creates stability in the standing knee joint which should resist any pressure applied by the tree leg foot.

And lastly, tree pose can be practiced with the tree leg actively working to hold itself up, rather than passively leaning against the standing leg. (Picture the leg lifting itself, rotating, and placing the foot on the opposite leg all on its own, without the help of your hand, and then holding itself up there.) In this scenario, the tree leg’s foot would actually be placing no pressure on the standing knee at all.

Upon closer examination, it becomes clear that the classic teaching that foot-on-knee placement in tree pose is inherently “bad alignment” is a questionable belief that probably does not apply to most bodies in this pose.

 


HEADSTAND (SIRSANA)

Another controversial asana in the yoga community is headstand (sirsana), a movement that many wonderful and well-meaning yoga teachers believe should never be practiced because our cervical spine is simply not designed to carry the full weight of our body in such a fashion.

It is absolutely the case that most Western bodies are not adapted to handle the loads that headstand places on their cervical spine. (This is why teaching full headstand to a group class is definitely not advisable!)

But if we look at headstand as a movement that applies certain loads to the body, and if we understand that the tissues of our body adapt to the loads they experience, we begin to realize that if someone were to intelligently and progressively load their cervical spine over time (and it would need to be slowly and over a lot of time!), it would be possible for their body to adapt to the loads of headstand. Sirsana would be a safe asana for this body to practice. It's therefore an oversimplification to state that headstand is an inherently bad movement. It would be more accurate to say that it is simply a movement which many bodies are not currently adapted to handle (but they could be trained with time!)

 

CONCLUSION

When we start thinking about movement in terms of load instead of inherently “good” or “bad”, we gain a more nuanced perspective on the body. It’s true that any movement with high enough loads can injure us, but low load positions that we frequent regularly are unlikely to be the source of damage and pain in our body because our tissues will respond by adapting to handle them. These realizations lead us away from viewing our body as an innately fragile structure that is vulnerable to damage from suboptimal forces, and instead as the strong, resilient, and adaptable organism that it truly is.

Pelvic-Tucking and Lumbar Flexion: Movements We Shouldn't Do In Yoga?

Last year, I wrote two separate blog posts addressing an unhelpful trend I had noticed in the yoga community: the over-use of the pelvis-tucking cue by yoga teachers. Instead of offering the instruction to tuck one’s pelvis only when doing so would specifically enhance the anatomical intention of a pose, many yoga teachers (and yoga teacher training programs in general) were treating the pelvis-tucking cue as an almost universal action that students should be working throughout their entire yoga practice.

In today’s blog post I'd like to address this same alignment issue again, but this time from a surprisingly different perspective. Since the time that I wrote these two pieces, I have noticed that this pelvis-tucking message has grown much more widespread in the yoga community, which is a wonderful progressive step for us. However, this shift in perspective has brought with it a large population of yogis who are now taking a stand on the complete opposite end of the spectrum from the original issue. Today, I regularly hear yoga teachers report that they “never teach to tuck the pelvis”, that they have dropped this instruction from their teaching language altogether, and that tucking the pelvis and the accompanying flexion of the lumbar spine that occurs are “bad” or “harmful” movements for the body and should not be practiced.

As well-intentioned as such viewpoints are, they are unfortunately not an improvement over the original situation. Instead of treating this as a black-or-white “to tuck or not to tuck” issue, I’d like to suggest that we move toward a nuanced approach to pelvic movement that takes into consideration the individual asana in question and the individual body being taught in the moment.

 

WHAT EXACTLY IS A PELVIC-TUCK?

First of all, let’s take a brief look at the anatomy of a pelvic tuck so that we can make sure we’re all on the same page when we talk about this term. Technically called a “posterior tilt of the pelvis”, this action takes place when the pelvis rotates backwards (or posteriorly) in the sagittal plane, which is the anatomical plane in which we view the body from the side. When this happens, the tailbone moves down and forward while the pubic symphysis (the place where the two pubic bones meet in the front of the pelvis) moves forward and up toward the navel.

Here’s a quick video of me demonstrating a pelvic tuck because visuals are always so helpful!

 

WHY DO MANY YOGA TEACHERS NOW BELIEVE WE SHOULD NEVER TUCK OUR PELVIS?

Many teachers have misinterpreted the messages calling for a more judicious approach to pelvic-tucking (like those of my original articles) to instead be messages calling for the cessation of all tucking everywhere by everyone. But aside from this, some yoga teachers have concerns about the flexion of the lumbar spine that happens when our pelvis tucks. Here’s a quick visual demonstration of this - do you see how when the pelvis posteriorly rotates, the lumbar spine naturally moves into flexion?

There is a widespread belief in the yoga and movement world that lumbar flexion is an inherently damaging movement for the body. (I used to believe this idea myself some time ago too!) The general claim is that spinal flexion puts an unhealthy amount of pressure on the lumbar spine which can lead to harmful conditions like joint degeneration, ligament sprains, and disc herniations. I’ve even heard statements like “Your spine is like a credit card. Repeatedly flexing it is like bending a credit card over and over - with enough time, the credit card will simply break.”

It turns out that cautions like these are based on a “lever system” model of the body which is limiting in its scope and is quickly becoming outdated. This model views the body, and especially the spine, as an inherently fragile structure that is quite vulnerable to injury when it experiences compressive forces. But a more current and accurate model of the body is that it is a naturally resilient biotensegrity structure whose tissues are supported three-dimensionally and have the ability to adapt to the demands placed upon them, thereby becoming stronger and better able to withstand load in the future.

Forces affect biotensegrity structures like the human body (new model) differently than they affect lever systems like machines (old model). Of course if the spine were to experience a high load while in a position of flexion (like in heavy weightlifting, for example), it could certainly be injured. But basic unloaded and low-loaded spinal flexion is a safe and natural movement for healthy spines.

When we pathologize a particular movement and tell people that it is inherently damaging, we create a significant amount of fear around that movement. When we have fearful beliefs about a movement, our brain is more likely to output pain for us when we do that movement (also known as a nocebo). This pain very likely has nothing to do with any actual tissue damage being caused by the movement, and instead has everything to do with beliefs and fear surrounding the movement. This will result in our participating in the movement less and less (sometimes called fear avoidance), which can cause us to lose mobility and range of motion in that direction of movement. (For more on this fascinating topic, you might be interested in viewing a workshop I recently taught on the anatomy of healthy spinal movement!)

 

IN CONCLUSION…

Beliefs about pelvis-tucking and lumbar flexion have moved from one end of the spectrum to the other in recent times. A current trend in the yoga world is to not teach or practice this movement at all because it is inherently harmful to our bodies. I am hopeful that our yoga community will settle on a more nuanced, less fear-based view of this issue in the near future. Our pelvis and spine and their adaptive, resilient tissues were designed to move in many different ways, and to keep these areas healthy and functioning well, we should move them in all of these ways on a regular basis. And when it comes to the specific yoga asanas that we teach or practice, we should let our anatomical intention for each pose - and not a one-size-fits-all rule - determine the pelvic positioning we teach.

 

 

FURTHER READING & EXPLORATION

If this is the first time you’ve heard this progressive message about lumbar flexion, here are a few suggestions for further reading and exploration on the topic:

-Jules Mitchell, M.S. - Watch her online class called Limber Lumbar (great name!) on the websites Udaya or Yoga Anytime, or even better, take her excellent Science of Stretching lecture series!

-Literature review research article: “To Crunch or Not to Crunch: An Evidence-Based Examination of Spinal Flexion Exercises, Their Potential Risks, and Their Applicability to Program Design” by Bret Contreras & Brad Schoenfeld

-Spinal Flexion Is Important for Low Back Health and Strength by Dean Somerset



Related Post: A Biomechanics-Informed Response to Yoga Journal: We Do Not Need To Tuck Our Tail In Every Yoga Pose

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Related Online Workshop: Anatomy of the Spine for Increased Core Connection