[Microblog] Anatomy Geek Stretching Thought of the Day

ANATOMY GEEK THOUGHT OF THE DAY: We often think of a muscle contraction happening only when a muscle *shortens*. But muscles work just as often as they lengthen - picture your hamstrings and the way they lengthen while they work 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.

One of the core rules we tend to learn in our yoga teacher trainings is that after we've "worked" a muscle or muscle group, we should stretch that muscle group to "balance it out". But because muscles can and do actually contract through all of their ranges (short, long, somewhere in between, etc.), is it skillful to consider the opposite of a muscle contraction a *stretch*? Do these two "balance" each other out? If it turned out that they were not necessarily opposing actions, would this change the way you sequence your yoga classes at all?

Enjoy pondering this one, and feel free to let me know how it goes!

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OUTDATED MODEL OF PAIN

One reason that the "bad movements" belief is unhelpful is that it is based on an outdated model of how pain works.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.

Does Traditional Yoga Lead to Muscular Imbalance? (Part 2)

Part 2 of my Yoga International article on yoga's strength imbalance was published today! I'm lucky to have been able to reference the work of several of my amazing teachers in this piece. I'm also more than grateful to Yoga International for embracing and sharing the positive message that while yoga is a fantastic practice for us, it isn't a "complete" one from an anatomical perspective, and there are a lot of other great movements out there that we can do to round things out. I hope you enjoy!

Does Traditional Yoga Lead to Muscular Imbalance? (Part 1)

I am MORE than excited about my new article in Yoga International that was just published today! Whoo-hoooo! It's Part 1 of a 2-part series and I really like how Yoga International summed it up:

"Yoga is often described as a balanced and complete long-term health and wellness practice. But does a consistent yoga practice really provide the body with everything it needs to function optimally? Yoga teacher Jenni Rawlings explains that although asana is a wonderful and transformative practice, when explored through the lens of anatomy, there is one aspect of this practice that is surprisingly unbalanced. But don't fear! In this article, she'll not only elucidate what this imbalance is but also how practitioners can undo it. Take what you learn and enhance the safety and overall function of your practice today!"

Fact Check: Will Strengthening Your Tight Hamstrings Make Them Tighter?

In any given yoga class, we are bound to practice an abundance of poses which stretch our hamstrings and relatively few that actually strengthen them. This rarely-discussed imbalance in yoga sequencing tends to occur for two main reasons.

First of all, there simply aren’t that many yoga asanas out there which strengthen the hamstrings in a meaningful way. Even if a yoga teacher wanted to focus specifically on hamstring strengthening in a particular class, she would have very few options in the traditional yoga pose canon from which to choose. Second, yoga teachers are well aware that many of their students have “tight” hamstrings, and there is a conventional belief in the yoga world (and in the fitness community in general) that it is not advisable to strengthen “tight” muscles because it will only make them tighter.

Today we’ll focus on the latter of these two issues: the idea that we should avoid strengthening our tight muscles because they are already tight. This is a very common and completely understandable belief among yogis. After all, one of our foundational goals in our yoga practice is to cultivate balance in our body. With this goal in mind, one of the last things we would want to do is create more tightness in an area that was already tight-feeling to begin with.

 

BUT WHAT DO WE MEAN WHEN WE SAY “TIGHT”?

Surprisingly, the widely-used term “tight” often means quite different things to different people. The following are all possibilities for what someone could be describing when they say they are “tight”:

-they aren’t able to stretch very far in a given direction
-their actual experienced sensation of their muscles when they stretch is “tight”
-the general, perpetual state of a specific muscle or group of muscles in their body is tight (i.e. “my hip flexors are tight from sitting so much”)
-they experience a vague sense of achiness or discomfort somewhere in their body (i.e. “my low back feels stiff and tight”)
-something else entirely :)

The reality is that there is ultimately no science-based definition for the word “tight”. The term is a very subjective one that each person experiences uniquely in his or her own body. This lack of an actual physiological definition for “tight” throws into question the very basis for the “strengthening tight muscles makes them tighter” belief. If there is no clear mechanism for what “tight” is, any rule about the body based on this concept begins to lose its meaning.

 

ARE TIGHT MUSCLES SHORT MUSCLES?

Although the notion of “tight” lacks a physiological definition, one commonly-shared belief about tightness is that the muscle(s) in question are shorter than they should be, and the natural solution to their “tightness/shortness” is to therefore lengthen them back out by stretching them.

This has been the dominant paradigm regarding stretching and “tight” muscles in the yoga world (and the fitness community in general) for many years. In my 2-part blog post series Stretching Is In Your Brain, I discussed that in contrast to this “short muscles that need to be lengthened” idea, a more updated, research-based perspective on stretching is the notion that our body’s flexibility is instead governed by our brain and central nervous system via a mechanism called stretch tolerance. [See study.] In summary, our inflexibility is not due to physically short muscles - it is instead due to our brain putting the brakes on our movement because it perceives that any deeper of a stretch will not be safe for us (and it’s probably right!) The “tightness” feeling that we experience at the end of our stretch is not the feeling of short muscles reaching the end of their length, but of an output of our brain in response to our stretch designed to signal us to stop the movement.

Isn’t this a fascinating and possibly mind-bending new way to approach the body in terms of stretching and our yoga practice?

 

STRENGTHENING THOSE TIGHT HAMSTRINGS

The hamstrings muscle group: biceps femoris, semitendinosus, & semimembranosus. (Image courtesy Real Bodywork, Inc.)

The hamstrings muscle group: biceps femoris, semitendinosus, & semimembranosus. (Image courtesy Real Bodywork, Inc.)

Paradigm-shifting aside, let’s return to the main topic of this article, which is the common belief that strengthening a tight muscle will make it tighter. In the same way that we tend to believe the outdated idea that our inflexible muscles are “short”, we also tend to believe that strengthening a muscle will physically alter that muscle so that it becomes shorter.

For example, the hamstrings might be the number-one-cited area of “tightness” in the average body. (But remember that “tightness” is a non-specific term without true scientific meaning.) If we believe that our hamstrings are “tight” because they are short, and if we also believe that strengthening muscles will physically shorten them, then there is no way that we would ever think that strengthening our short, tight hamstrings is a good idea. Tight plus tight equals more tight, right?

In addition to the example of the hamstrings, here are a few other areas of the body to which we often apply this same logic:

-our hip flexors are short from too much sitting, so we shouldn’t do hip flexor-strengthening moves

-our spines are rounded-forward (hyperkyphotic) from too much slouching, so we shouldn’t practice traditional abdominal work because it would shorten our abdominal muscles and pull us into more of a slouch

-our calves tend to be tight from high-heel (and other positive-heeled shoe) wearing, so we wouldn’t want to strengthen our calves because it would further tighten them

These arguments would absolutely make sense if we were still operating under the paradigm of physically-short muscles that we lengthen back out by stretching. But in the same way that we now understand that stretching a muscle doesn’t make it “longer”, we have also learned that strengthening a muscle does not make it “shorter”. Or to be more accurate, there is very little (if any) evidence to support the idea that strengthening a muscle causes it to structurally change so that its resting length becomes shorter.

As counterintuitive as it may seem (believe me, I know!), strengthening muscles does not “tighten”, “stiffen”, or “shorten” them - it doesn’t decrease their flexibility in any way. [See study.] In fact, if we strength train our muscles eccentrically (which means that our muscles are active as they lengthen), this has been shown to actually increase their flexibility. [See study.] So not only does strengthening a muscle not physically shorten it, but if done correctly, it can increase its stretch tolerance. This seems so contrary to popular thinking, but once we understand that our muscles only do what our powerful, communicative, and dynamic central nervous system tells them to do, these concepts begin to make more intuitive sense.

One important note is that while strengthening doesn’t stiffen our muscles, it will stiffen up our connective tissue (which is distinct from, although interwoven with, our muscle tissue) - but this is actually a desirable outcome. As I discussed in Stretching Is In Your Brain Part 2, we want our connective tissue to be stiff so that it can be strong, resilient, and less vulnerable to injury.

IN CONCLUSION...

In circling back to the overarching question of this article: no, strengthening your tight/short hamstrings (or any other muscles) will not make them tighter/shorter. But it will make the connective tissue of your hamstrings stronger and less prone to injury. This is especially relevant for yogis, given the high incidence of hamstring pulls and strains we experience in the yoga community as a result of the traditional sequencing of lots of hamstring stretching and very little strengthening. With this new knowledge about muscle physiology in mind, we should feel encouraged to strengthen any area of our body we might have previously been avoiding because we were afraid it would “tighten” up as a result. This change in approach will represent a path toward greater body awareness and the true balance that so many of us seek through our time on the yoga mat.

 

Related Online Workshop: Re-Imagining Hip-Openers: A Yoga Anatomy Workshop

Related Online Class: Hips-Focused Practice #2

The Easiest Mistake to Make in Backbends

I am sooo thankful to have published a second article in Yoga International! It's all too easy to do backbends in a way that will make your spine mad at you :), and I hope this article will provide lots of helpful info for how to approach these poses in a way that will offer true positive change in your body. Thanks so much for reading, guys!

https://yogainternational.com/article/view/the-easiest-mistake-to-make-in-backbends

In other news, I'm working on a new series of posts for my blog on shoulder mechanics in yoga. I haven't written specifically about the shoulders here yet, so I'm hoping that these posts will help fill in some missing info on this important area of the body. Stay tuned for this and more great movement info to come!

My Article on Fascia in Yoga International!

I'm so thankful and honored to have published a piece in esteemed Yoga International on some great information for yogis about fascia, our body's amazing connective tissue system that weaves us together on the inside. Check it out if you have a sec, guys! And then move your body in lots of different ways today to keep your fascia healthy and rad.

https://yogainternational.com/article/view/yoga-anatomy-what-every-teacher-and-practitioner-should-know-about-fascia

In other news, Part 2 of my "Stretching Is In Your Brain" series of articles is due to be posted here very soon. The subtitle of this one will be "What is the Value of Flexibility Without Strength?" Isn't that a good question to ponder? :)  I'm excited to share the piece with you soon!