by Jenni Rawlings
In yoga, we tend to place a lot of emphasis on stretching as a means toward more flexibility. But what actually happens in our body when we stretch? Most of us envision our bodies as consisting of play-doh like tissues that we pull on and make longer through stretching, but new science is revealing to us a model of stretching that is much more complex, dynamic, and fascinating than what has previously been imagined. And it turns out that thinking of our bodies in this older “play-doh” like version may be counterproductive and can lead to a number of injuries and structural problems resulting from our yoga practice. In order to keep our wonderful yoga tradition evolving and current, it’s important that we understand this new and fascinating science of stretching and any implications it might offer for our practice and teaching.
A NEW PARADIGM OF FLEXIBILITY
Biomechanics-based Restorative ExerciseTM teaches a lot of new and eye-opening information about stretching and flexibility that isn’t yet common knowledge in the yoga world. Additionally, the wonderful yoga teacher Jules Mitchell is on a mission to educate the yoga community about the science of stretching. Her recently-completed master’s thesis in exercise science is a comprehensive literature review of the most current scientific research on stretching to date, and it’s full of an abundance of important information for yogis.
Utilizing the innovative knowledge that these resources offer, let’s examine some of our current beliefs about stretching and introduce some helpful ways we can begin to update these beliefs to reflect the newest scientific word on the street.
WHAT WE THINK HAPPENS WHEN WE STRETCH
Most people think of their muscles as being either “long” or “short”, and that during a stretch, they are targeting their “short” muscles by physically “lengthening” or “loosening” them. In this stretching paradigm, our muscles are mold-able tissues like taffy or play-doh which we can form into a shape of our choosing by simply pulling or pushing on them. For example, when we fold forward into paschimottanasana (seated forward fold), we tend to imagine that our hamstrings are physically growing longer in that moment of our stretch in the same way that taffy would grow longer if we tugged on both of its ends for awhile. We imagine that when we release paschimottanasana, our hamstrings remain just a bit longer than they were before we did the stretch. And we also imagine that the longer and deeper we hold a pose like paschimottanasana, the longer and looser our hamstrings become.
This stretching paradigm is what most of us were taught in our yoga classes, workshops, and teacher trainings. It’s completely understandable that we might see the body as working like this, but new research is revealing a very different version of the biomechanics of stretching.
THE NEW SCIENCE OF WHAT HAPPENS WHEN WE STRETCH
We all know that when we stretch, we experience a feeling of “tightness” at our end range of motion – a sensation that limits us from moving any deeper into the stretch. We have traditionally defined this “tight” sensation as the result of having reached the end length of the muscle(s) we’re stretching. In other words, we pulled on the ends of our muscle until we reached its maximum physical length, and once we hit that boundary, the stretch stopped and we felt the “tightness”. With enough stretching, we could increase the length of our muscle and therefore move further into our stretch with time.
But we now understand that increasing our flexibility has much less to do with the physical length of our muscle tissue, and much more to do with the part of our body that controls and moves our muscles: the nervous system. Our brain, the main control center of our nervous system, is in constant communication with our muscles and one of its main imperatives is to keep our body where it perceives it is safe. Normal movements that we make throughout our day are considered safe by the brain because it knows and trusts them. But on the other hand, our brain is not familiar with ranges of motion that we never move into, so it’s much less likely to consider those places safe. When we stretch, if we move into a place that the brain isn’t familiar with, our nervous system will end our stretch by communicating with our muscles to put the breaks on the movement.
For example, if you happen to work on your computer for 8 solid hours a day (and if you don’t take frequent intermittent stretch breaks for your shoulders – hint hint 🙂 ), the brain becomes very familiar with the arms-forward position that you use while typing and considers that range safe. Then later, if you decide to do a chest stretch in which you take your arm out to the side and then behind you, the brain doesn’t feel that that movement is safe because you so rarely go there, so it will limit your range very early on in the stretch.
A major takeaway from this new flexibility paradigm is that when we increase our range of motion through stretching, it isn’t because we pulled on our tissues and made them longer. It’s because we visited the edge of our stretch (also called stretch “tolerance”) enough times that our brain started to feel comfortable there and it began to allow us to move deeper into that range.
OKAY, I THINK I’M STARTING TO GET IT, BUT WHY IS THIS IMPORTANT?
It’s definitely interesting and more scientifically accurate to understand this previously-overlooked role that our nervous system plays in flexibility. But whether it’s your nervous system or the physical length of your muscles limiting you in a stretch, why does it matter? Isn’t a stretch a stretch, regardless of the mechanism behind it?
That’s a great question – I’m so glad you asked! The main answer has to do with what tissues are being targeted when we stretch. We often think and talk about stretching our muscles in our yoga poses (i.e. paschimottanasana stretches our “hamstrings”), but in truth our muscles are surrounded by, interwoven with, and inseparable from our fascia. Our fascia is our incredible body-wide web of connective tissue that is literally everywhere inside of us, and it includes our tendons and ligaments. Muscles and fascia are two distinct tissues with different properties, but both are affected when we stretch. And how we choose to stretch, which is based on whether we believe that we’re physically lengthening our muscles (old paradigm) or increasing our nervous system’s tolerance for the stretch (new paradigm), determines how our fascia will be affected during the movement. (Preview for Part 2 of this post: if we’re going with the older “pulling on our tissues like play-doh” paradigm, we’ll feel more drawn to stretching deeper and harder in our poses, which is much more likely to simply damage our tissues than give us the flexibility we seek.)
I’ll elaborate more on this and other important topics, like how we might choose to apply this new information to our yoga practice and teaching, in my next blog post. Stay tuned, guys! And in the meantime, if you’re interested in further reading, check out this awesome article by Jules Mitchell (written for a pretty science-oriented reader). See you for Part 2 soon!
- Integrity In Your Movement: Hips vs. Spine
- Hypermobility vs Flexibility: Do You Know the Difference?
- How to Keep Everyone Safe and Happy in a Mixed-Level Yoga Class
- R.I.C.E or M.E.A.T: What To Do When Recovering From Injury For Yogis and Non-Yogis Alike
This is fascinating! I can’t wait to read more posts in this series.
previously overlooked by the transgressist mode so common for the modern, otherwise no. but good information; thank you.
A lot of this is well known in the yoga world. Kurz’s stretching scientifically explicitly described yoga stretching in very similar terms back in 1987 and I’ve lost count of the number of yoga teachers who’ve discussed reading it since.
Still an interesting article but all the “everybody is wrong and only my trademark system has the truth” stuff grates at the best of times and more so when it’s more a matter of “some people still don’t know this and here’s some relatively recent detail”
I don’t quarrel with the information, but as stated in an earlier comment, it’s not really news. Practically every yoga teacher I’ve ever worked with has given instructions to go into an asana, hold it for a little while, and then you find you can go deeper. This increases over time. I suggest checking out Ray Long’s website and blog: http://www.bandhayoga.com/
I love your blog! I, myself, am very much a fan of yoga, and I recently wrote about it in my blog on inspiration and fitness. Here’s the link if you would like to check it out : https://wordpress.com/post/83566352/33/
Have a great day! 🙂
Sorry about the bad link! Here is a working link to the blogpost. https://inspirationcreationstation.wordpress.com/2015/02/25/lets-exercise/
WOW! Thank you so much for posting this. I honestly learned so much just with this quick post! I love how easy this is to read and comprehend.
The author never claimed it was new info, and said it was the fruit of a literature review.
So what happens if we test the range of motion of unconscious people or dead people (or other animals)? A Japanese filmmaker studied photographs of corpses on a battlefield, and he said they were always twisted in ways that living actors could not duplicate. So it does sound as if ange of motion increases upon death.
I aam eager to find out what variations on stretching help the brain to feel safe. Repeated visitation of end of range (=gentle bouncing)? Alternating tension and relaxation of the targeted muscles while at end of range? Calm music? Massage or rubbing the skin while at end of range? Visualization?
“So what happens if we test the range of motion of unconscious people or dead people (or other animals)? A Japanese filmmaker studied photographs of corpses on a battlefield, and he said they were always twisted in ways that living actors could not duplicate. So it does sound as if ange of motion increases upon death.” Rod
If you are dead, I don’t think you are going to be limited by anything physical. Of course, the body will assume any position when it isn’t living. You could probably cross someone’s arms on their backside or lop their leg over the neck.
Now I have to wonder: in people with split personalities or multiple personalities, can the different personalities have different ranges of motion?
This article is fascinating, not so much from the “new” science it presents (which isn’t new), but more from the M.O. it uses to market the “new” system. To wit:
“For example, when we fold forward into paschimottanasana (seated forward fold), we tend to imagine that our hamstrings are physically growing longer in that moment of our stretch in the same way that taffy would grow longer if we tugged on both of its ends for awhile. ”
I rather doubt that anyone–yoga teacher, student, person walking down the street or Drs. Kurz or Long (mentioned above)–thinks that muscles behave like taffy. Many of us engage in stretching (and also yoga) quite frequently–and teach it. We are also well aware of the various factors involved.
Nevertheless, the M.O. of this author (and her apparent mentor) seems to be to mischaracterize others work by implying that they are presenting something as ridiculous as this. Then present the “new discovery” (trademarked, of course and promoted by friends as “game changing”).
Apparently, such details as the fact that none of the authorities on stretching have ever characterized stretching or muscles behaving like “taffy” or the fact that the “discovery” has been described by others for years is not particularly important to this author. Here’s a quote from a 2012 blog post by Dr. Long (mentioned by George above):
“In addition, many factors contribute to the way a muscle lengthens, including the viscoelastic properties, creep (a type of deformation that has been postulated for fascial elements), psychological factors (such as muscle memory and tolerance), and extramuscular links to synergists. Individual muscle architecture or shape also plays a role.”
He also has the scientific references at the bottom, which address all of the factors the author of this ridiculous and non-yogic article now characterize as “new”.
Essentrics technique takes this all in to consideration to totally rebalance the body:)
Everything about stretches and how every muscles have to be stretched and relaxed are clearly explained in ancient scriptures such as Gita, Patanjali’s Yoga sutras and Upanishads. Traditional Yoga teachers who understood these knowledge know how to to teach. Only the modern yoga teachers who do not give importance of understanding the Philosophy and applying while practicing instead practice yoga as physical exercises are ignorant and end up with injuries.
Hi. Under general anesthesia, which essentially blocks the nerve/muscle synapse causing paralysis, one’s range of motion is increased 100 fold. Why? As this article points out, our brain sends out constant messaging concerning movement, proprioception, much of it is inhibitory. We need to work with it to create our most effective movement