Excerpt from Anthony P. Arnold, PhD, Rhythm and Touch, the Fundamentals of Craniosacral Therapy, North Atlantic Books, Berkeley, 2009.

What Is Craniosacral Therapy?

The term craniosacral refers to the practitioner's focus on the spinal column, the bones of the head or cranium, and the broad ending structure of the spine, the sacrum. As an evaluative and monitoring tool, craniosacral practice pays particular attention to the craniosacral rhythm, a slight swelling and contraction of the bones of the head, and a rotation around a central axis by the skeleton on each side of the body.

Figure 1. The Central Column: Sacrum, Spine, and Cranium. Within the human skeleton, the sacrum, spine, and cranium form a flexible central column. The entire column responds to the craniosacral rhythm and transmits this rhythm to the other bones and tissues of the body.

This regular movement is apparently generated by pressure changes throughout the head and spinal column during the production and absorption of cerebrospinal fluid. The craniosacral rhythm can be palpated throughout the human body at a rate of four to twelve cycles each minute. It offers a useful clue to the condition of soft tissue and joints throughout the body, and furnishes a diagram to patterns of pain and discomfort.

Yet, this important indicator of harmony or disharmony within the total being is barely utilized or even recognized by modern medical practitioners. As mentioned above, because the craniosacral rhythm is so subtle, difficulty in its perception serves as one of the main stumbling blocks to the vast realms opened by means of craniosacral practice. Patience and a degree of inner harmony are the most powerful keys to opening this realm for the new student.

Another important element of this practice is the fascia. All body parts are encased within a network of fibrous connective tissue. This varies from very thin, weblike film to many layers of specialized membranes. The most obvious of these is the cutaneous membrane, our outer skin. Internally, these varied protective membranes are called fascias.

A wonderful aspect of the body's fascia or connective tissue is that the entire network is interconnected and continuous. Thus, for example, the fascia surrounding the heart is connected and continuous with the fascia surrounding the lungs, arteries, nearby ribs and muscles, and, indirectly, with every other bodily organ.

The nerve material of the brain and spinal cord is covered on its surface by specialized fascia. This extends out onto the nerves and helps modulate nerve electrical qualities.

More important to our present interest is the inner lining of the skull and spinal column, especially the dura mater. This dense fibrous connective tissue lines the cranial vault, the bones surrounding the brain, and the nerve canal within the spinal column. This continuous sheath provides the chamber in which the cerebrospinal fluid circulates around the brain and spinal cord, from the top of the head to the end of the spine.

Together, the dura mater and the cerebrospinal fluid provide a cushioning and insulated environment for the important functions of the brain and spinal cord.

Yet, this protective membrane is itself vulnerable. As with any protective coating, the protective device itself can begin to collect evidence of stress. As a tent may begin to show wrinkles and sags while still protecting its occupants, so the dura mater, or any fascia, begins to show patterns of tightness and flexibility.

Within the human body, it appears that tension and strain patterns in the muscles and fibrous connective tissue are at the base of improper alignment of the bones. Prolonged tightness and inflexibility of the fascia or muscles creates a slight but steady pull on the bones, restricting movement and even shifting the bone from proper alignment. This is experienced as recurrent pain, propensity to repeated injury in the same place, and resistance to simple manipulative treatment. If a skilled practitioner realigns the bones themselves, relief may be temporary, because the connective tissues are transmitting to the bones a set of forces that gradually ease them out of alignment again. Craniosacral practice addresses the connective tissue more explicitly, eventually easing the internal stress and allowing the total system to rediscover a more harmonious alignment.

In the head, the dura mater is addressed, using a light touch on the cranial bones. In the trunk of the body, hands are applied in a number of crucial regions, called diaphragms. These are areas of the body where crosswise muscle and connective tissue predominate. Stress held in such tissue can contribute to misalignment or restriction. An obvious example is the respiratory diaphragm connecting across the lower ribs. Other diaphragms are located at the floor of the pelvis, across the shoulders, and at the point where the head and neck join.

Craniosacral practice is accomplished by careful attention to the rhythmic and energetic manifestations of the body. Gentle touch is applied in harmony with the indications received from the body, on the cranial bones and at the diaphragms. Craniosacral therapy originated within a tradition of physical manipulation. In some schools, strong pressures are still used for this work. Yet, the body often resists a forceful approach and responds readily to gentle touch. Essentially, this is a very simple therapy, a type of "laying on of hands,” emanating from many years of sophisticated observation and experiment, and based on a profound attentiveness to and respect for the processes of the total person.

In craniosacral practice the craniosacral rhythm indicates symmetry, the bones serve as positioning devices for the therapist's hands, and muscle or connective tissue softens as physical harmony returns.