Precise manipulative treatment of the cranium begin in the 1930’s with the work of an osteopathic physician, Dr. William C. Sutherland. Dr. Sutherland showed that the skull, instead of being a solid box, is capable of movement across the joints (called sutures) between the twenty-two bones which make up the skull. He further showed that these movements, although small, occur in a regular rhythm. This rhythm is probably generated by the fluctuation in pressure of the cerebrospinal fluid which surrounds the brain and spinal cord. The normal rate of the rhythmical impulse is between 8 and 14 cycles per minute. It occurs throughout life and represents an independent physiological rhythm, different from both heartbeat and respiration.
The motion of the cranial bones, under ideal conditions, is smooth balanced and symmetrical in both the expansion and contraction phases of the cranial rhythm. Motion in any cranial bone can be impaired by lack of resiliency within the bone itself, lack of free mobility along its sutures, lack or distortion of motion in other cranial bones or by restrictions in the dural membranes which line the cranial cavity and surround and support the brain and spinal cord. This dural envelope descends in the spinal canal to the sacrum at the base of the spine, where it is firmly attached. Hence, the sacrum is considered a part of the cranial mechanism and its functional integrity impinges on that of the cranium.
The causes of restrictions in the cranial mechanism are numerous. Chief among them would be trauma : falls, blows, fractures, concussions, whiplash injuries, etc. Others include dental extractions and dental surgery, severe infectious diseases, particularly meningitis and encephalitis, chronic drug use and stress. An especially potent cause of trouble is birth trauma, e.g. from malpresentation, narrow maternal pelvis, forceps delivery or vacuum extraction, prolonged labor with excessive molding of the skull or precipitous labor. The fetal skull is part bone and part membrane and cartilage. This renders it vulnerable to distortion during the birth process and this, uncorrected, may persist into adult life with adverse consequences for the normal growth and development.
The effects of cranial restrictions are too varied and far reaching to list exhaustively, but they range from migraine and other headaches, eye pain, visual problems, TMJ pain and “popping jaw”, facial neuralgia, ear infections, tinnitus, deafness, dizziness, tics and facial paralysis, spinal curvatures and back pain, to depression and other emotional and psychological disturbances.
In infants and children, cranial restrictions can be responsible for complaints such as squints, repeated ear infections, digestive and respiratory difficulties, convulsions, clumsiness and inco-ordination as well as emotional or behavioral problems, and learning disabilities. Research work amongst grade school children carried out at the Michigan State University College of Osteopathic Medicine has shown clear correlation between the number and severity of cranial restrictions and the occurrence of dyslexia, learning disabilities, disturbed behavior, hyperactivity and autism.
Cranial manipulation is always quiet. It involves very light contact with the patient s head or sacrum. The use of force or strong pressure is not necessary. The physician senses the restrictions with his fingers. He then, directed by the patient s own cranial rhythm, works to allow the restricted motion to return to normal. The patients lie comfortably on the back and are often known to fall asleep during treatment. As the majority of problems have present for many years, it is usually necessary to give a series of treatments before positive results can be established. Ideally, treatment should be given as early as possible to prevent problems arising following injury either at birth or in later life.