Yoga Anatomy: Top 5 Movement Science Insights for Teachers

April 13, 2017    BY Jenni Rawlings

These are five of the most eye-opening insights I have learned from anatomy, physiology, kinesiology, and pain science; they have given me a much different perspective on the body than the one I learned through my yoga studies alone.

Consider each of these insights simply my best effort at a summary 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.

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. I hope you find these ideas interesting and inspiring both in your own yoga practice and in any teaching you do!

Movement science insight #1: Stretching and 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." This rule is based on the belief that when a muscle contracts, it is shortening. Therefore, the reasoning goes, 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 while 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). When a muscle contracts as it lengthens, this is called an "eccentric contraction," and we move this way all the time in our normal human movements.

Because muscles can and do actually contract through all of their ranges (short, long, somewhere in between), 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 good or bad.

Last year I wrote an article called “Are Some Movements Inherently Bad?” that basically suggested that no movements are inherently bad, that 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 as “corrective exercises” that are thought of as "better," more "functional," or "healthier" for the body than the way we usually move. But the reality is that movements don't have inherent value that makes them "better for you" or "worse for you" except within the specific context of who is practicing the movement and with what goal.

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, worse, or more or less functional than other yoga poses and movements. Context and individualized goals are the best 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 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] do not always correlate either.)

It turns out that the human body is more resilient and adaptable than previous models of alignment and pain have taken into account. 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.) 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 the risk of injury. 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 loads are not enough to inevitably cause injury in most bodies. For example, if someone’s front knee drifts inward a few centimeters in warrior II (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-over-wrist” alignment 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 long-term 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 used too much fear-based language around alignment in yoga.

This insight follows directly from the previous one. 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 II to protect your knee” or “Press your pubic bone into the floor in salabhasana to keep your low back safe.”

As well intentioned as they are, warnings like these might 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. 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 less pain. And, conversely, the more we believe that our bodies are innately fragile and vulnerable to injury from low loads and small “misalignments,” the more likely our beliefs are to contribute to increased threat levels and increased pain.

In warrior II pose, stating that keeping the knee directly above the ankle is important “to protect your knee” is a potentially noceboic suggestion to offer to our students. (The opposite of a placebo, 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 salabhasana “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, noceboic language about alignment in our yoga classes, consider talking about alignment in terms of what it helps us achieve in our poses. For example, for warrior II, we could say, “Keep your front knee lined up over your ankle to engage your lateral hip muscles,” and for salabhasana, we could say, “Press your pubic bone into the floor to lengthen your low back and direct the backbend into your thoracic spine.” These types of cues utilize alignment more for load optimization and less for injury prevention. Instead of instilling in students a sense of fragility about their bodies, these types of cues encourage increased body awareness, which can be confidence-building and empowering.

Movement science insight #5: We can stop using two common yoga cues in particular.

We often teach yoga poses in a way that tells our students which specific muscles they should (or should not) be using 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 recruits can often interfere with our built-in, sophisticated motor control system in a way that results in less efficient movement.

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

1. The glutes and bridge/wheel: There is no need to tell our students to "soften/relax your glutes in bridge and wheel” or to 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). 

2. Arms overhead and 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. 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 five insights with an open mind, and I hope to see you on the mat virtually or in person in the near future!

(If you're interested in how you might embody these insights in your yoga teaching, consider trying some classes in my online class library, which is a great resource that contains not only my practices but those of wonderful science-minded yoga teachers I admire.)

Jenni Rawlings
Jenni Rawlings is a yoga teacher with an emphasis on anatomy, biomechanics, physiology, and movement science. You can find out more about her offerings and teachings at