One of the key diagnostic tools for a Craniosacral Therapy practitioner is the Craniosacral rhythm. The Craniosacral rhythm is one of many rhythms that are palpable within the human body but the most subtle. For instance, it is easy to detect one's own heartbeat, and breathing rhythms but to determine the rhythm of the Craniosacral system requires patience and practice.
What is the Craniosacral rhythm? Everyone has a Craniosacral rhythm. In fact, all vertebrae animals have one. The rhythm is a result of the ebb and flow of cerebrospinal fluid as it is being produced and reabsorbed in and around the central nervous system. This rhythm is typically between 6-12 cycles per minute and can be felt throughout the body.
The filling and emptying of cerebrospinal fluid follows "The Pressurestat Model". This term was coined by Dr. John Upledger as it mimics a semi-enclosed hydraulic system. This system is closed but still has an inflow and an outflow apparatus. When fluid is supplied into a container, it expands until it can no longer hold fluid and is expelled. In the case of the Craniosacral system, the fluid container is a very strong and flexible membrane known as the Dura Mater that surrounds the brain and spinal chord. (it is known as the Dural Tube when it is surrounding the spinal chord). The fluid in this pressurestat model is the cerebrospinal fluid. The structures that monitor inflow and outflow are neuromechanical receptors which detect stretch and compression forces and are located in the sagittal sutures in the skull. These intelligent detectors signal the emptying and filling of cerebrospinal fluid.
When the rate of inflow exceeds the rate of outflow, a signal is sent from the stretch receptors to temporarily halt the production of cerebrospinal fluid. Once the pressure receptors sense the bones in the sagittal suture (parietal) begin to join, a signal is sent to resume the production of cerebrospinal fluid.
The filling and emptying of cerbrospinal fluid is known as flexion (the widening or filling of the cranium) and extension (emptying or narrowing) . During the flexion phase, paired bones rotate externally and single bones move inferiorly (towards the feet). In extension, paired bones rotate internally and single bones move in a superior (towards the head) direction.
What is the cerebrospinal fluid made of? This fluid is the result of refined blood that is filtered out by specialized apparatus called Choroid Plexuses located in the brain's ventricular system. The importance of cerbrospinal fluid is to provide mechanical protection in the form of shock absorption, regulate the pH environment of the central nervous system, distribution of neuroendocrine factors, and prevent ischemia (narrowing) of the spinal chord. It is even thought cerebrospinal fluid contains chelating factors as well. Chelating factors help eliminate harmful heavy metals in the body.
When the Craniosacral System is functioning optimally, the rhythm is akin to that of a subtle tide. Irregularities and asymmetries in this rhythm are used as a detection tool to locate imbalances in the body. Craniosacral Therapy practitioners are trained to evaluate the Symmetry, Quality, Amplitude and Rate ( this is known as evaluating the SQAR) of the Craniosacral rhythm. They are evaluated as follows:
Where there are disturbances in the Craniosacral rhythm, symptoms can develop. For example, a left leg that doesn't rotate outward during the flexion phase, may indicate an imbalance or restriction in the fascia near the hip flexors and hip joint. A practitioner who is trained in Craniosacral therapy can help the body reestablish its optimal movement patterns as restrictions are released. Restrictions are released with minimal and non-evasive touch. This touch is typically 5 grams or less.
Despite it's name, Craniosacral therapy is not just relegated to treating the Cranium and Sacrum. It is a whole-body approach to well-being. Releasing restrictions throughout the body can encourage better output of cerebrospinal fluid and positively effect the function of the Central Nervous System. A balanced Central Nervous System can lead to an optimally functioning and balanced individual.