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WG Sutherland, Cranial motion and the Primary Respiratory Mechanism

William Garner Sutherland was a student of Dr AT Still (the founder of Osteopathy).

Sutherland graduated from the School of Osteopathy in 1900, and through his musings over an observation of a disarticulated skull, he began to take a journey into the motion of the cranial bones of the head as well as the reciprocal motion of the sacrum (which will be described below).

Sutherland would always credit his discoveries and development of Osteopathy in the Cranial field to Dr Still’s teachings, and as has been mentioned in a previous post, these teachings were deeply influenced and indeed grounded in the Intelligence of nature and our connection to the earth.

Below is an excerpt from his book ‘Teachings in the Science of Osteopathy’:

“As I looked at a disarticulated adult mounted skull that belonged to Dr Still, the detail in the articular surfaces of the sphenosquamous sutures caught my attention..”

He was talking about the “beveled” design of the human temporal bones, which overlapped the parietal bone. “I became impressed with the idea that this suture was a display of a design for motion.” The squama of the two temporal bones looked like the gills of a fish, that the next thought seemed so logical…“That they were made for respiratory motion….”

Could the bones of the cranium, of the cranial vault and the cranial base display a type of motion, of respiratory motion? And with that could the spinal cord, encased in the vertebral column, connecting with the sacrum and the Ilia, also display reciprocal motion?

Whilst around the time of Sutherland’s discovery (1900), it was recognised that at birth, the bones of the head (osseous tissue) are held together by cartilage and membrane in order for the infant head to adapt to the maternal passageway, there was no doubt that there was bone movement then!

Yet it was thought that in the adult cranium, the bones would fuse, and no movement was possible.

Initially, Sutherland began his journeying into the respiratory movement of the cranium by intricately studying the human skull, and in doing so began to refine and soften the osteopathic manipulative techniques to the cranium.

“I became like a watchmaker in developing a delicate technique. I learned to take things apart from the articulated skull and put them back together again after I came to understand the mechanism…

The day came when I sent a paper I had written to a professor in Kirksville for review. His reaction was prompt. He said that the bones of the skull cannot be pried apart with a crowbar! However, at the time when I received that reply I already had in my possession two little temporal bones, including the petrous portions, that I had been able to remove from an articulated skull specimen with the small blade of a penknife.”

“…a crowbar would have been too big an instrument for such a delicate mechanism. If you understand the mechanism, there are wonderful possibilities in store for you! If I had not to stick to my own nose and dig, I would probably be skeptical today…”

Sutherland did not have the equipment to monitor on someone else’s head any discreet movements in the bones, and nor did he want to experiment on another to have only someone’s experience relayed back to him. He was adamant that he needed to know himself, and to feel the experiences of what would happen if he applied pressure to the bones in his head or changed the angle of the sacrum.

“I went to find something simple regarding a Primary Respiratory Mechanism in the body”…

Sutherland found that placing a pad under the apex of his sacrum when lying down would move the sacrum into a flexion position, then if he moved the pad to the base of the sacrum, it would move it into the extension position, and leaving it there, he could feel changes in his head that showed the connection between the sacrum and the “normal fluctuation of the Tide”.

“I sought some kind of mechanism through which I might perform what I call the inhalation position of the sphenobasilar junction….” The sphenobasilar junction is at the cranial base, which could not be reached directly. Sutherland needed to feel this move by applying pressure to the cranial vault bones, such as the parietals. Sutherland designed a contraption from an old football helmet, adding straps and hemostats to it and began experimenting on his own head if he added pressure and restriction to certain bones of the cranium. Below is his description of what happened when adjusting the straps and hemostats to “lift” the parietal bones of the cranium. “As I turned the hemostat’s, the helmet would lift the parietals laterally and upward…and as I released the tension, the bones went back of their own accord.”

He also used a butter bowl to apply pressure (via straps) to the greater wings of the sphenoid (these can be palpated at the temple of the human) to apply from the cranial vault, a “side-bending” motion to the bone which could also be felt down to his sacrum.

After some time of wandering around with a home-made cranial motion experiment on his head, Sutherland found that he could NOT prove the theory that the cranial bones fuse and do not move in adult life, because in fact they did. And they do so in a discreet, reciprocal and breathing motion.

Osteopath Viola Frymann published a study on the rhythmic motion of the living cranium (1971), followed in later years by other studies; Norman St. Pierre at all (1976), Upledger, Carni et al (1983). And more recently studies in 2006, and 2021 have also identified a rhythm, and movement that exists alongside of heart and respiration.

“The measurable amplitude of the cranial wave ranges between 0.001 and 0.005 inches (40 microns to 1.5mm).

This “breathing motion” can feel restricted or inert where there has been physical and emotional trauma (sudden or built up over time).

Much of Sutherland’s work was dismissed by mainstream medicine and even in Osteopathic circles due to it being experiential and not “proven.”

For students who are learning Cranial Osteopathy, or Craniosacral therapy, it is through the development of inner stillness, sensitive palpation, and experiential practice that the student is able to develop the ability to detect the more discreet movements in the head, and in fact in the whole body.

A minute measurement of 0.001 can feel like a large movement, a respiratory motion within a bone when the practitioner is in a still and meditative state.

Sutherland’s digging for further knowledge also led him to discover a tide-like motion within the body, and the Breath of Life which is a bigger presence and manifests itself through Primary respiration.

“A central aspect proposed by Sutherland was the PRM (Primary Respiratory Mechanism) UNITES and CO-ORDINATES the fundamental physiology of the Human body to the level of cellular metabolism:” (2021).

There is a lot of language in both Cranial Osteopathy and Craniosacral Biodynamics, Cranial Rhythm, CRI, Primary Respiration, PRM, Mid-Tide, Long-Tide, Breath of Life to name a few.

To make things simpler; if you can imagine “Rhythms within Rhythms … and that “we are polyrhythmic beings” (Sills). Each rhythm suspended and interconnected within the next.

If you can imagine the “breathing” motion of a jelly fish underwater, or a flower, its petals opening and closing; healthy (non-restricted) cranial bone motion would feel like that, and where it doesn’t, then the role of the practitioner is to help facilitate improved motility within the tissues and fluids.

Sutherland described from his experiments and research the Primary Respiratory Mechanism (PRM) below:

The Involuntary mechanism, the PRM: expresses the understanding that the subtle fluid and tissue motions palpable in the human system are driven by an inherent life force and not by voluntary processes or outer agencies.

1. The mobility of the cranial bones.

2. Reciprocal tension membranes.

3. Motility of the CNS.

4. Involuntary motion of the sacrum between the ilia.


Teachings in the Science of Osteopathy. Sutherland WG, lectures given 1949-1950.

The Heart of Listening, Visionary Craniosacral Work, Vol 1. Milne, H (1995).

Foundations in Craniosacral Biodynamics. Sills, F (2011).

Studies for further reference:

A study of rhythmic motions of the living cranium (Frymann) 1976.

The detection of relative movements of the cranial bones (St. Pierre, Roppel, Retzlaff) 1976.

Examination of the Cranial Rhythm in Long-standing and coma patients (Carni, Upledger et al)

Recording the rate of the CRI (Nielson, Sergueef, Glonek) 2006.

Direct Measurement of the rhythmic motions of the human head identifies


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