Yoga's Stretch Continuum
What Is A Motion Continuum?
In chiropractic, teachers use the graph to the right to depict the range of safe movement that joints can go through. Movement initiation at a singular joint starts the diagram and then the scale grows outward as motion increases at that same joint. The chiropractic version depicts where joint mobilization, manipulation, or joint injury would lie on the scale. On the original diagram, the neutral position is no movement, active range of motion is the movement that a person alone can create, and passive range of motion is the extra movement a joint can go through with someone else's influence and over pressure. Para-physiologic space is where chiropractors bring a joint to produce the cavitation (sound) of an adjustment, just safely and quickly beyond the limits of a physiologic barrier. Anything before that space is mobilization and anything after that is an injury to the supporting soft tissue (the anatomic barrier). Chiropractors are trained to adapt their manual therapy based on the limitations of each body type, taking into consideration that patient's overall joint flexibility and previous injuries.
Because I am trained to look at moving joints like this, I was inspired to alter the adjustment continuum to portray the stages of stretching that we experience during yoga asanas, the physical portion of a yoga practice. Is it a researched and exact science? Absolutely not. BUT......I think the image introduces a few cool concepts that many people would not assume is going on during a seemingly musculoskeletal activity and I utilize researched information in each stage to explain them. Similar to the chiropractic continuum, my version of this diagram is a generalization to portray bigger picture ideas; Not every person has the same degree of joint mobility or tissue lengthening. Let's dive into each section for a better description! The chiropractic version is depicted above and my new version is below:
The Sections Of The Stretch Continuum
#1- Not Moving
I think this stage is self-explanatory without getting into a discussion of seemingly stationary poses like balancing postures (which really are hundreds of tiny micro-movements stabilizing you) or meditative positions (which may seem physically stationary but mentally and energetically, are extremely active). So over all, you're not producing motion. You nailed it.....moving on.
#2- Pain Free Motion
The beginning of movement initiation and the stretch cycle is an easy and familiar range of motion that you barely notice. There is no physical stretch sensation along the muscles or joints because a you aren't near the final destination of the stretch and you have a memory of this movement being simple. Your brain has completed this motion numerous times and now has stored an expectation of how it feels; it recognizes what you are trying to accomplish and the body knows where you're going. The nervous system coordinating the movement in this stage remembers feeling effortless because you've previously wired the motor patterns to properly coordinate the joints, muscles, and balance necessary to return to the pose on command.
Everyone has a different degree of tissue flexibility and bony alignment based on their genetic build, developmental movement patterns, previous injuries, and present occupational positions. For some, yoga is a natural progression of an old activity like dancing or cheer leading so they have a larger range of pain free motion before reaching the later stages. For less active individuals or novices, the range of pain free motion may be extremely tiny or non-existent. As you dedicate yourself to a consistent and long-term yoga practice, this stage just grows and grows and grows. New poses get added to this continuum and your threshold for finding a stretch in any positions rises. For the extremely experienced yogis, they may actually have a hard time finding a muscular stretch sensation during an entire class!
#3 - Resistance
For most of us during the physical portion of yoga, we are extremely familiar with stages 4 and 5, the actual discomfort during a stretch. Before that discomfort though is a brief period of simple resistance. Our body notices a change is happening and it's not alarmed yet, just alert. This resistance is pain free and the body is recognizing nearing the end of a mentally or physically-set effortless range of motion. I think this is where most people stop their stretch and progress to a different pose either because the fast pace of a flowing class, distracted unintentional movements or fear of being uncomfortable. Throughout this article, I'll use the word uncomfortable as I describe the physical sensations of a pose. I am not talking about earth shattering pain that you should push past to get deeper into a stretch. Pain is a wonderful sign from the body that something is wrong and you need to address it.
At home, we use the term Tensegrity to explain the necessity for pain. Tensegrity is an architectural term describing the homeostatic way that a structure stabilizes itself against counteracting forces of compression and tension. When applied to a moving body, it explains the perfect distribution of forces between muscles, bones, and
tendons to create flawless, balanced, and painless shapes. Along the continuum of joint motion, proper joint positioning and support will minimize the prevalence of soft tissue injuries and bone deformity caused by the shearing of muscular imbalances. When a joint is moving properly the involved muscles and tendons can withstand the stresses that they were built to accommodate AKA yoga doesn't hurt, it nourishes. Let's dive into a little physiology to understand why your body may prevent a stretch from continuing past this stage of resistance.
Within every muscle belly is a stretch receptor known as a muscle spindle that detects changes in length of the muscle as you move. At both ends of the muscle belly where it attaches to a bone via tendinous junction, lie more stretch receptors known as Golgi Tendon Organs that detect change in tension to limit excessive muscle contractions. The connection between muscles and bones are entrusted to the strong tendons because they have protective mechanics built in to prevent you from stretching past a safe limit, which would hurt one or both of the two worlds the tendons connect. Both types of receptors detect and send information about the changes in muscle length or tone to the nervous system for a response. As you start to stretch, a signal is sent to the brain to resist the stretch to prevent the muscle from over stretching or tearing. This is why you should never force the body into a stretch, you are actually increasing the intensity of the system put in place to resist a stretch due to the contraction.
#4- Physical Discomfort
In this stage, you've gone past the initial resistance from your neuromusculoskeletal system and are feeling the full sensation of the pose telling you that you've reached a challenging yet safe depth of stretch. Yoga is a very physical experience and can be very uncomfortable. For those new to yoga, not only are you learning how the body works, you are also witnessing how your body doesn't work. Awakening a body awareness is an amazing first step that will only continue to progress as you keep practicing, which in time will decrease the physical discomfort.
"There is this idea in some yoga circles that we have to force ourselves into a pose. Yoga must be modified to fit you, not the other way around."
- Indra Devi
I find that many people start learning yoga as a way to decrease the pain of their existing injuries. Maybe manual therapy didn't help or they are fearful of surgery so yoga seems like a logical and non-invasive way to better connect with your body while decreasing the pain associated with movement. When I first started yoga I knew there were going to be limits. I had torn my hip labrum in college playing soccer and forever more just assumed that I'd have hip pain and poor motion in that joint. Before every class I would tell the instructor, "this is my bad hip that doesn't bend well" so they wouldn't come over and try to push me into pigeon pose. Pigeon pose was the bane of my existence because I could feel discomfort in the exact area where I had had pain before the surgery. I convinced myself that because of the discomfort, it was a sign from my body that I was pushing too far and that I must be re-injuring the area. I avoided any deep hip poses that could pinch my hip capsule for about two years and looking back now, I missed so much time for growth and progress. Once I received the correct physical treatment and found the emotional support needed to break a barrier, I was ready to face my fears and move past self-given limitations.
"You truly cannot progress in yoga or life if you avoid the uncomfortable positions, period."
-Marina Mangano, DC
One major reason that the subconscious body will limit your joint mobility is due to unstable or misaligned joints. Joint centration is a term that describes the perfect position for a joint to be placed in so that the supporting muscles that are evenly centered around the joint can fire together in unison. This safe contraction holds the articulating bone perfectly in place and makes it super stable. When a bone is not sitting correctly in a joint "socket," muscle imbalances are created resulting in altered range of motion, usually limited motion. In yoga postures or when trying to improve a joint's mobility, you cannot push past joint limitation if the body does not feel structurally supported. If certain muscles are not firing properly and stabilizing the joint correctly, it will never fully release to allow you to move in a direction that could injure you. Once the mechanics supporting a joint are restored and properly stabilized, the flexibility of the surrounding muscles can be accessed then trained to become more flexible. One underlying limitation that often goes hand in hand with anatomical ,why do we stop ourselves when we feel the discomfort? That answer takes us into the next section, emotional pain.
#5- Mental Discomfort
Physchosomatic pain is a term used to describe how mental processes can result as a physical symptom even when a physical ailment or condition is not present. Similar to the description in the first phase, the brain remembers movements by closely intertwining the motor patterns together with the memory of how the movement feels. In the pain free range of motion the brain remembers simplicity and ease but movement memory applies to all ranges of motion, positive or negative. Past the point of pain free movement, your body sends updates to the brain to prepare itself for a movement or position that it has previously associated with difficulty or discomfort. The limbic system in the brain works closely with the theme of physchomatic pain; when emotional memories of previously painful movements are stirred and brought to the surface from your subconscious, you will feel an "old" pain or unresolved injury.
The amygdala in the limbic system stores emotion for memories which then cannot be separated in the body from experiences of movement memory. Author Annie O'Connor, describes that personal contact and emotional support play a big role in coping with life stressors which influences how we all experience levels of physical pain. Even if you do not have access to these things in your life at home or at work, you are offered both in a yoga studio.
The fear of injury, re-injury, or being in discomfort peak here at this stage. It is the portion of deep poses when you'll see students in a yoga class experience an emotional release like crying, shaking, or having a panic attack. If we can control our body in an aligned, safe position for long enough and fight the mental resistance, some of the emotions will release. The surface level and conscious biomechanical actions influence our unknown, unconscious physiological reactions. Stretching triggers the release of physiologic, neuroendocrine factors such as endorphins into the bloodstream. (3) Endorphins go through the body to find receptors on surfaces of cells within the central nervous system to trigger relaxation and a good feeling, what yoga should feel like. So desensitize your stretch mechanism and protective system by slowly working into each unpleasant pose with safe alignment, proper support or adjustments provided by someone else and watch the response you feel normalize in seconds.
"When we have fear or anxiety the brain sends negative signals and we are over powered by such feelings. If we have faith or confidence in our body, the brain sends positive signals to promote healthy movement or healing. In medicine, we call this the placebo effect but in ancient yoga it's called sraddha."
- Kausthub Desikachar
#6- Tissue and Joint Remodeling
If you've reached this point in a yoga poses then you've gone through all the healthy stages of a stretch. You stretched further then you thought possible...it was uncomfortable...you shook, you held your breath, you panicked and maybe even cried..... but now this. The moment you broke the physical and emotional barrier to experience the true benefit of each yoga pose. It wouldn't be transformative if you skip all that work and got right to this stage of tissue and joint remodeling. That is the real yoga for me, going through the cycle of human emotions to reach the rewarding and satisfying sensation of progress, success, and self control. Once your mind and body can reach this point of a yoga pose, you start to breath again and sink deep. You'll feel the right parts of your body stretching and learn to play with micro-movements that allow you to stay there longer than you thought possible, furthering the depth and release. If you never bring your body to a soft tissue limit, it can never progress. Just like building muscle tissue during strength training. Small micro-tears of the muscle fibers are necessary to create new lengths and build bigger muscle cells. Basic exercise physiology states that your body adapts to the demands placed on it like in Davis's law which describes how soft tissue remodels and changes due to the imposed demands of activity. Closely related to Wolff's law that focuses on how osseous tissue (bones) heals after trauma (big or little) to strengthen itself and better respond to future mechanical stresses. Basically, the active compression we experience in a yoga class will slowly alter the tissue in our body to function appropriately in the motions you are asking of it. Not in a few days time of course, but over a long period of consistent and regimented practice.
Repetitive end range forces happen at the final limit of each yoga pose. For example, when you back bend as deep as possible then your body politely stops you but your instructor offers a strap which gives you the ability to use manual pressure to pull even deeper until your body violently opposes going any further. That blocked limit after introduction of external pressure is end range spinal extension. To improve the flexibility of joint tissue, we must create micro-injuries that are constantly healing - lengthening - healing - lengthening - healing - lengthening as we practice each day. According to a classification in McKenzie Mechanical Diagnosis Therapy, producing pain is the goal for remodeling dysfunctional tissue in hopes of providing stresses to the involved connective tissue at the end range of joint motion to create enough load to transform the tissue safely. (1)
"Increasing stress to the scar tissue will ensure appropriate tensile stresses are applied to the joint for future resistance preparation."
- Annie O'Connor
The remodeling phase of healing can take from 21 days to over a year after an actual injury which we'll discuss more in depth in the next section but understand that the soreness you feel after a yoga class is your body repairing the tissue form microtraumas you created from deep stretching. (2) This is why beginners should avoid buying that 10 DAYS UNLIMITED YOGA plan. You will be sore and at a certain point, continuously stretching the fibers that don't have time to heal in between classes can create weakness and vulnerability to injury. Start at a slow and moderate frequency until you don't have heavy soreness after class anymore. Then challenge yourself to more advanced poses or higher frequency of classes, building your stamina and yoga endurance.
#7- Safety Limit
When the body is pushed past a safe limit, injury ensues. The brain will then create memories of the pain and tissue disruption caused by this particle movement as a specific sequence of receptors. In the future, if you try to recreate the same sequential motor pattern, the receptors spark stored memories in the brain and pull up a red flag or alarm system. The body remembers that this leads to an injury and will lock down any stabilizing muscle it can recruit to prevent another attack on itself. Numerous attacks like this are necessary to prevent injury yet the system responsible for getting fired up to protect you is the sympathetic nervous system. This system is in control of all things stressful in the body and opposes one of the major goals of a yoga practice....decreasing neurological stress. Repetitive stressful triggers like this takes away from the benefits of yoga which is trying to restore your parasympathetic system and calm the mind body connection. The more injuries that your body withstands (if not properly treated and corrected) it can't help but become anxious, jumpy, and defensive. Your threshold for pain tolerance decreases as the brain perceives increasing amounts of movement associated with pain. In a sense, it loses trust in movement and those providers that encourage you to move.
Yoga is a powerful, helpful tool. Use it appropriately and it works wonders. Use it carelessly and inappropriately and you could hurt yourself or others.
- Kausthub Desikachar
#8- Tissue or Joint Injury
To describe what happens in this stage I'll use the word nocioception, what you experience when the body senses tissue damage and transmits pain signals to the cortex of the brain. (3) The structures surrounding a joint are innervated to continuously report back the events of the joint. Capsular ligaments, intervertebral discs, even blood vessels have nerves that can experience and report nocioception irritated by extreme temperature, inflammation, or mechanical movement like in yoga. (2) Ligaments that connect bone to bone, unfortunately never fully restore their initial strength against forces once they've been injured. Healing processes like scar tissue and disorganized collagen fibers alter the optimal function of this support system post trauma so they have a harder time bouncing back compared to muscles and tendons. Tendons that connect muscle to bone, are slow to heal after an injury because "it was a long time coming." This injury is usually the result of continuous and excessive forces that degenerates the tendon as opposed to one hard blow in a single incident that hurt the tendon. For most power sports, muscle fibers can return to full use pretty quickly in a concentric manner, meaning when the muscle is firing without lengthening. For us yogis, muscle "pulls" may take a while to feel normal due to the eccentric nature of yoga. Most yoga poses are a combination of concentric muscle contractions (muscle used to start the motion while shortening) and eccentric muscle contractions (muscle used to resist and stretch while we lengthen it).
Yoga instructor Moises Aguilar puts it very simply, "Yoga is so freaking hard because you are using the same muscles to create a motion that you are also trying to stretch." The more advanced you become during yoga asana, the more conscious control you'll gain over this phenomenon. "The more aware and in tune you become with your body, the better you become at coordinating the relaxation of the agonist (primary movers) muscles, allowing a stretch of the antagonist muscles (opposing and counteraction muscles). " - Ray Long
You'll know when you've reached this stage of joint movement and it is filled with immediate regret. You've gone too far, by accident or intentionally, so now it's time to go seek the proper treatment to expedite the healing process and minimize permanent damage to your physical being.
"Pain is inevitable; suffering is optional."
- Buddhist Proverb
I am happy to have envisioned this stretch continuum because for me, it will become the basic graphic to represent the foundational knowledge that I currently have of the body and the world of yoga. As I continue to learn philosophy and supporting science for the physical portion of yoga, I'm sure I will come back to the graph to alter it and add substance into each section. I may even remove or erase sections! Until that more evolved version of myself comes around I hope that you are all able to follow along through the sections, identifying with and questioning parts of each. Please share with your yoga friends and comment below to help build on this continuum!
Long, Ray. The Key Poses of Yoga. Print. Pg. 3-24.
O'Connor Annie & Kolski, Melissa. A World of Hurt: A Guide to Classifying Pain. Thomas Land Publishers. 2015. Print. Pg. 68
McKenzie Method Of Mechanical Diagnosis & Therapy Lumbar Spine. 2015. Print. Pg. 10