A controversial manipulative-therapy approach for humans is making headway into the treatment of animals. At the time of its discovery in the early 20th century by William Garner Sutherland, DO, craniosacral manipulation "was generally regarded as the dream of an erratic."1
Over time, the approach made inroads into the osteopathic profession. In 1947, students of Sutherland formed The Cranial Academy www.cranialacademy.org, whose membership comprised physicians and dentists dedicated to the research and promotion of osteopathy in the cranial field.
The popularity of craniosacral therapy widened after John E. Upledger, DO, broke from osteopathic tradition and began teaching the technique to non-physicians.
According to Upledger Institute Inc. (www.upledger.com) craniosacral therapy treats traumatic brain and spinal cord injuries, orthopedic problems, "motor-coordination impairments," chronic back pain, colic, neurovascular and immune disorders and "post-surgical dysfunction."
For several years, the Institute has been offering courses in craniosacral therapy for animals, including workshops on dogs, wolves, foxes, coyotes and horses.
The fundamental tenets of the technique hold that the bones of the cranium and pelvis exhibit subtle, periodic motions as a result of the rhythmic coiling and uncoiling of the central nervous system and their subsequent tugs on bony attachments inside the skull and sacrum.
The motions of the occiput and sacrum caused by these dural pulls then supposedly produce mechanical responses in the tissues with which they communicate, ultimately spreading throughout body. Because the motions are so subtle, the craniosacral therapist "listens" through the hands for these motions through contact with the patient's head or sacrum.
If therapists detect asymmetric movements or abnormal rates, they commence treatment through gentle motions designed to release strain patterns in the dura. Their goal is to promote more healthful and restorative movement patterns.
These visually imperceptible movements have posed challenges to researchers attempting to identify, verify and quantify the ebb and flow of the craniosacral mechanism borne by the tide of the cerebrospinal fluid.
Arguments persist about whether the human cranial sutures ossify during adulthood. If the cranial bones fuse, especially at the critical fulcrum located at the junction of the sphenoid bone and occiput, that would call into question a key component of craniosacral manipulative therapy.
This premise maintains that the rocking back and forth of the occiput as a consequence of dural connections at the foramen magnum induces secondary, gear-like motion in its rostral neighbor, the sphenoid bone. This requires that the suture between the sphenoid and occiput remain unossified.
Whispers of Controversy
The cranial concept further posits that all other cranial bones move in synchrony. The unpaired cranial bones flex and extend while the paired bones rotate internally and externally.
Because the dural tube surrounding the spinal cord connects both at the occiput and sacrum, an examiner at each end of the patient should theoretically be able to report the same findings.
However, a number of studies have indicated that the diagnostic reliability between examiners is practically non-existent, and no scientific evidence has demonstrated treatment effectiveness.
The approach remains shrouded in controversy today, even to the point where some researchers consider the craniosacral phenomenon to be purely imaginary.2
Given the unanswered questions about craniosacral manipulation in humans, how well-justified can the procedure be for non-humans?
Only species-specific research will answer these questions. To this end, Kevin K. Haussler, DVM, DC, Ph.D., at the Equine Orthopedic Research Center at Colorado State University has completed a preliminary investigation into the anatomical basis of craniosacral therapy in horses.
He presented his findings at the fourth annual Veterinary Spinal Manipulative Therapy Convention in Fajardo, Puerto Rico, in November.
He methodically compared claims of craniosacral proponents to available scientific evidence with a focus on veterinary anatomy, refuting widely accepted premises.
Concerning sutural ossification, Dr. Haussler demonstrated that, in skull after non-human skull, the basisphenoid articulations are commonly ossified. Dr. Haussler then presented videotaps from his own recent anatomical dissections of the equine spine and dural attachments.
He clearly illustrated differences in dural mobility at key sites along the spine, from the occiput to the sacrum, that debunk several assumptions.
For example, in response to the idea that the spinal dura acts like a tube and that traction forces on the dura at one end transmit faithfully to the other end, Dr. Haussler showed that dural attachments at each spinal nerve level impede the conveyance of even gross arcs of motion (much larger in magnitude than the subtle craniosacral motion) applied to the neck from reaching the pelvis.
In addition, when the cervicothoracic region is brought into extension, the dura exhibits bidirectional movement in the cranial thoracic segments, a phenomenon unheard of in craniosacral therapy.
Plea for Prudence
Perhaps before more non-veterinarians set up workshops teaching others craniosacral therapy of wolves and horses, it would be prudent to examine further the technique's anatomical underpinnings.
In the words of anatomy professor Steve E. Hartman, Ph.D., and physiology professor James M. Norton, Ph.D., both from the College of Osteopathic Medicine at the University of New England, "[W]e believe that craniosacral therapy bears approximately the same relationship to real medicine that astrology bears to astronomy.
"That is, this approach to 'health care' is medical fiction, and it is not appropriate to teach fiction as part of medical or allied health curricula. [U]ntil researchers have replicated demonstrations of efficacy using properly controlled scientific trials we believe that craniosacral therapy/craniosacral osteopathy should be removed from all medical and allied health curricula."3
Dr. Robinson, DVM, DO, Dipl. ABMA, FAAMA, oversees complementary veterinary education at Colorado State University.