Summary of C.R.I. Rates Research Paper

The term 'Cranial Rhythmic Impulse' (CRI) is used to describe a slow pulsatile movement phenomena that the body exhibits. The purpose of this study is not to confirm, deny or debate the existence of the CRI, but to present and analyse published material on this topic. CRI numerical values, as reported by various authors, vary widely and do not correspond with the experience of this author when palpating the cranial rhythm. This research paper will examine these apparent discrepancies with a view to clarifying the situation regarding the rate of the CRI. "Learn to carefully scrutinize the information about the cranial field, and the cerebrospinal fluid in particular, so as to criticize scientifically. Do not base your thinking on matters that have been passed down through the ages without critical scrutiny." (Sutherland 1990 p7)

CRI is a term coined by Dr's John and Rachel Woods in 1961 to describe the phenomena of movement that the Primary Respiratory Mechanism produced in Sutherland's model (p1129 in Ward). It is thought that the CRI is not the complete and only functional consequence of the PRM, but that it is a physical (as opposed to chemical or electromagnetic) manifestation involving pressure and motion variables. The exact etiology of the CRI remains unclear from a reading of the literature.

All references to the rate of the CRI known to this author have been tabulated for ease of comprehension. See Table 1. Where these rates are based on experimental studies, various parameters have been presented for comparison. See Table 2. An examination of these tables shows great variability in the types of study, the methods used and the results obtained. "There exists a wide range of disagreement amongst experts as to what is and what is not normal regarding rates of pulsation." Chaitow (2) p28

Previous research studies have numerically defined the normal rate of the Cranial Rhythmic Impulse. This review of the literature has sought to identify, tabulate and deduce that this range of values is great if the same phenomena, measured in the same way, is authentically described by each study cited. Put another way, the vital question is: does an experimental study that measures a mean CRI rate of less than 4 c.p.m. accurately refer to the same phenomena as that which another author contends is 14 c.p.m.?

In theory, the phenomena of the CRI is of relevance to many specialised disciplines, such as the diagnostic sciences, anatomy, neuroscience, opthalmology, ear, nose and throat specialities, rehabilitation, psychiatry and counselling as well as to a popular awareness of this concept. In practice, it is body-oriented therapists who have the hand skills and the time to implement the appropriate methods. At present the phenomena of the CRI is largely unknown outside of a few specialised professions. Information relevant to this phenomena comes from the major source of clinically based osteopathic research and from a variety of minor sources in the biological and diagnostic sciences that have historically worked in parallel, not in tandem.

"Its diagnostic possibilities have never been fully explored." (Magoun p86) "Beyond the clinical interest of disorders such as hydrocephalus, knowledge of the rate and pathways of circulation, of the absorption and mode of origin of the fluid is needed for intelligent therapeutic measures within the central nervous system." (Flexner p420)

Researchers have urged that greater attention be paid to this area for decades. Interdisciplinary research that combines the theoretical and palpatory focus of 'Cranial Therapy' with the appropriate diagnostic technology may resolve some of the problems involved with CRI study as outlined in this paper. Objective measurement should be a priority.

Although palpation is the principal research tool used, measurement systems devised to record the CRI include pickoffs (Frymann), capacitance plates (St. Pierre), force transducers (Tettambel)(Retzlaff1975)(Cope), strain gauges (Upledger and Karni), infrared markers (Zanakis) and photogrammetry (Myers) The author is aware of research efforts using reflected laser technology and also a method employing light emitting diodes.

An objective measurement device that is simple and portable would enable fieldwork. Surveying of particular populations may allow correlative data to be recorded to determine the effects of palpation, the occurence of still points and to determine particular clinical relationships with greater certainty.

In summary, the CRI is a slow pulsatile movement phenomena, the rate of which is disputed by different authors and researchers. The use of different methodologies makes meaningful comparisons difficult. Further research that includes standardised measurement as a precondition may determine an accurate and reliable reference rate for the Cranial Rhythmic Impulse.

Malcolm Hiort 17/2/99