The Subtle Tide That Moves Within

By Kirsten Beverley-Waters for Yoga Medicine®.

Cranio-Sacral Rhythms Hold a Link to Therapeutic Yoga

The growing desire of our students to become self-healers has shifted teachers’ focus into slower flows and yin style classes to create a space for students to unwind, draw inward, and ride the wave of their breath. What if we could do more than speak to awareness and help create therapeutic shifts in how our students perceive pain, work through suffering, and connect with their nervous system?

The foundation of this technique resides in the power of the cranio-sacral connection. The founder of Osteopathic Medicine, A.T. Still, discovered that the connection between the cranium and sacrum held a key to deeper understanding in human health.1 Still compiled this into an article to shed light on how yoga teachers can employ concepts of Osteopathic cranio-sacral motion into a simple therapeutic yoga practice. The many complexities of this concept requires an understanding that this practice is only an entry point into this methodology.

Cranio-Sacral Rhythm

Cranio-Sacral Rhythm (CSR) is a subtle two-phase movement occurring throughout the body. Cranio-sacral motions consist of a flexion stage and extension phase. During the flexion phase, the cranium widens transversely, the sacral apex moves anteriorly (nutation), and the extremities rotate externally. During the extension phase, the cranium narrows in the transverse dimension, the sacral apex moves posteriorly (counter-nutation) and the extremities rotate internally.2 The flexion and extension are most apparent in the cranium and the sacrum. The teacher within me wanted to relate flexion and extension to pranayama and yoga but the mechanical motion does not always match the cranial rhythm. Instead, I focused on cardinal movements of the sacrum and began exploring how nutation and counter-nutation impacted the autonomic nervous system.

By observing an osteopathic physician treat patients using Osteopathic Manipulative Treatment (OMT), I was able to dig a little deeper into how I could modulate yoga postures to impact this rhythm. The physician explained that patients treated by an osteopathic physician through OMT rely not only on the cranial movement and an associated rhythm, but also with an ability to palpate that movement and rhythm. Treatment proceeds by mobilizing the cranial bones, the sacrum, and the dural tube. OMT helps facilitate the release of restrictions that may inhibit the functioning of the cranio-sacral system— the fluid membranes that surround the brain, spinal column, and nerves. These fluid membranes or sheaths of connective tissue around the nervous system and the brain, and in between those sheaths and the neurons themselves there is cerebrospinal fluid that absorbs shock, nourishes, and supports the nervous system.3

It became easier to envision the cerebral-spinal fluid mimicking an ocean tide and the cranio-sacral motion acting as a gravitational pull of the sun and moon. Osteopaths dial into the rise and fall of these tides in treatment. The tides and their pull impact the entire structural system of the human body, ultimately influencing its function.

Modulating the Nervous System Through Yoga

Three areas in which we, as teachers, can influence the autonomic nervous system are through the parasympathetic nervous system, the sympathetic chain ganglia, and the cardinal movements of the sacrum (nutation and counter-nutation.) By layering in pranayama we can accentuate the innate motions of the cranio-sacral rhythm.

A direct impact on the parasympathetic nervous system is experienced through the subocciput. The vagus nerve, the largest parasympathetic nerve in the body, originates proximally to this area and is influenced by the amount of tension occurring in the suboccipital region. By adapting a myofascial release technique in the subocciput to focus on the oculo-cervical reflex we can induce subtle muscular activation to enhance the release of this posture.

The other contributor to the autonomic nervous system is our sympathetic chain ganglia. Located on the rib angles and along either side of the spinal cord, the afferent (bring information to the brain) and efferent (sending information from the brain) nerve bodies regulate the flight or fight response. By placing two yoga blocks 1-2” apart in supported fish, or matsyasana, we can evenly distribute the applied pressure to the sympathetic chain ganglia. The result is a more direct influence on the sympathetic nervous system.

In order to completely address the parasympathetic nervous system and create a pathway through the entire spinal column we can take advantage of the cardinal movements of cranio-sacral motion (nutation/counter-nutation). These movements are created through the dura of the brain. This tough sheath that surround the brain and spinal cord attaches at the base of the skull, foramen magnum, and upper cervical vertebrae. Another firm attachment is the second sacral segment and then the tailbone self via filum terminal. Through this very hard mechanical connection you can influence by changing how we move in easy pose, sukasana, in what I call the Double Block Sacral Release.

For this modification, we add two blocks with a 1-2” gap between them just as we did in supported fish. The use of the double blocks and the firming of the sit bones on them allows for more dedicated sacroiliac/sacral motion. One notation that may be helpful when working with students is awareness of the amplitude in lifting the chest and hollowing the body. By keeping these movements small, almost invisible to the eye, it brings the focus to the superior cranial rhythmic actions rather than the postural (mechanical) axis.

Moving through this practice, we ride the cranio-sacral rhythm from the subocciput to the sacral release. This allows my students to move through some of the areas of greatest muscle restriction and tension in the body to ultimately settle into the quieter motions of cranio-sacral rhythm. Here, I have found that supported savasana provides the deepest connection to the more subtle sensations of respiration and muscular release. Giving space for extended savasana has proven the most beneficial to my students. Remember that cranio-sacral movements and releases can be fine-drawn but their impact on the autonomic nervous system is deeply therapeutic in practice.

1. Double Block Subocciput Release with Oculo-Cervical Reflex [Parasympathetic]

  • Set-up: Place two blocks into a “V” shape with the ends closest to the head elevated using a small wedge or weight to secure the blocks.
  • Lie down on your back and place the base of your skull onto the blocks. Bend your knees so they start in a knee-knock pose.
  • For more intensity you will extend your legs out.
  • Once you position take 3 deep breaths in through the nose and out through mouth to clear out any extra energy.
  • Muscular Activation: To start the release you will work through several positions of the eyes. Imagine a compass when moving your eyes. (North, South, East, West).
  • Take 5 slow breaths in/out through the nose with your eyes gazing in one direction. Repeat this process until you have gone up, down, right, left.
  • Conclude with gazing up at the ceiling for 5 breaths, then softly closing your eyes.
  • Allow 3-5 minutes in this pose.

2. Double Block Supported Fish [Sympathetic Chain Ganglia]

  • Unlike traditional supported fish you will orient your blocks in a vertical fashion with a 1-2” gap between the blocks. This leaves space for the spine.
  • Lie down on your back. Place the base of your shoulder blades on the bottom of the blocks and lean back. You can place your head on a third block to make yourself more comfortable or a bolster.
  • Find a comfortable position for your legs either in knee knock pose or savasana Allow 4-5 minutes in this posture.

3. Double Block Sacral Release (Nutation & Counter-Nutation)

  • Placing the sit bones firmly on the blocks with 1-2” between them to give space for the sacrum to move you will begin by placing your right pointer finger on your chin.
  • As you breath in draw your chin in and as you exhale extend the chin forward. Both motions are barely noticeable.
  • Layer in the pranayama with your movement. Breathe in, draw your chin back. Breathe out, your chin slides forward.
  • Drop your hands down to rest on your knees and add the final movement. As you breathe in, draw your chin back and lift your chest and create a small cow pose as the sacrum moves into nutation. Then as you exhale, extend your chin forward, and arch your back just enough that the sacrum begins to move into counter-nutation.
  • Continue this sequence for 2-5 minutes. Slow, focused breaths in/out through the nose.

4. Savasana

  • Place on block on its highest height at the back of the mat.
  • Place a second block 6-8” away from the first block on a medium height.
  • Lay your bolster over the blocks.
  • Bring your low back to the edge of the bolster and keep your knees bent.
  • Lean back and allow your spine to rest comfortably on the bolster.
  • Slowly extend one leg at a time and extend your arms out.
  • Stay as long time allows or a minimum of 5 minutes for a full body release.


  1. DeStefano, Lisa A. (2017). Cranial Technique. Greenman’s Principles of Manual Medicine (4, 159-161).
  2. Beal, Myron C. (1992). The Principles of Palpatory Diagnosis and Manipulative Technique. American Academy of Osteopathy, (2-4).
  3. Waters, K., DO, (2019, October). Personal Interview

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