da Vinci's Seat of the Soul

Research:  The Inherent Rhythmic Motion of the Cranial Bones.

Cranial bone motion has been the most controversial phenomenon of the Primary Respiratory Mechanism (PRM), but there is ample evidence that the cranial bones do rhythmically move a small but definite amount.

Historically, cranial bone motion was considered an anatomic impossibility. Respected scientists, anatomists, and anthropologists have always assumed that the cranial bones fuse and cannot move.

However, a thorough examination of the experimental data gives a totally different point of view.

Upon examination of Todd and Lyon’s data, the conclusion that cranial bones normally fuse is certainly in question.

Cranial bone motion in animals is well documented:

Cranial bone motion in humans is also well documented:

There are plans to expand this research utilizing a larger number of subjects.

Russian Space Research

Assessment of cranial bone motion carried out by the Russian cosmonaut programs used various types of radiographic (x-ray) and ultrasound equipment.

After being introduced to OCF, Moskalenko and associates carried out several studies which illustrated cranial bone motion:

Together, Moskalenko and Frymann29 carried this work toward the formulation of a theory that explains the physiology of the PRM.

US Space Research

In the mid-1990s NASA carried out research and developed an ultrasound device using pulse-phase locked loop (PPLL) technology with sensitivity to 0.1 µm, to more precisely assess intracranial anatomy and physiology.30-34

In their summary, the NASA research team stated, “Although the skull is often assumed to be a rigid container with a constant volume, many researchers have demonstrated that the skull moves on the order of a few µm in association with changes in intracranial pressure.” 33,34

Recent Osteopathic Research on Cranial bone Motion

When palpatory assessment of cranial bone motion is compared with simultaneous Laser Doppler Flowmetry technology, striking correlations have been found.

Instrument recordings of physiologic activity which correspond to clinical palpatory experience provide strong support for the concept of cranial bone motion and the PRM in general. This line of research is continuing.


Substantial support for life-long sutural patency and mobility of cranial sutures in healthy human beings is well established within the scientific and medical literature. Cranial bones can move small amounts, and do posses inherent rhythmic motion.

Left to Right: Viola M. Frymann DO, Yuri Moskalenko PhD, Kenneth Nelson DO,
Tom Glonek PhD, Toshiaki Ueno MD PhD, Frank Willard PhD.

The Cranial Academy and Sutherland Cranial Teaching Foundation sponsored a “PRM Research Symposium” in October 2003. Pictured is a panel featuring several of the most outstanding cranial osteopathic researchers.


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