Sphenobasilar Ranges of Motion

Charles L.Blum, DC

The movement between the sphenoid and the occiput has long been considered a primary focus in cranial therapeutic care. The sphenoid and occiput, which occupy two-thirds of the base of the cranium, is a point of attachment for the falx cerebri, falx cerebelli and tentorium cerebelli, the major dural structures in the cranium. Their connections with the petrous portion of the temporal bones create foramen through which pass the majority of blood vessels and cranial nerves. In the osteopathic model developed by Dr. Sutherland and later presented in books by Magoun and Upledger, the following "movements" occur between the sphenoid and occiput near or at the sphenobasilar junction:

Palpation of the various movements within the "sphenobasilar junction" utilizes common palpatory landmarks such as the greater wing of the sphenoid (bilaterally) and the base of the occiput (primarily the lateral angles as they approach the mastoid process). In testing for sphenobasilar movement, gentle pressure is applied to the cranium while simultaneously feeling for a response. With each direction of movement, the testing is performed in opposing directions to determine any restrictions. The amount, length, and degree of movement is evaluated. Much of this movement will be appreciated as a compliance or tissue resilience. This compliance to an initiating force should be balanced in all directions throughout the cranium, specifically as related to the sphenobasilar junction.

FLEXION/EXTENSION

With the patient lying in a supine position, and the examiner at the head of the table, the doctor contacts (bilaterally) the greater wings of the sphenoid with his/her thumbs while the occiput rests in the fingertips of both hands. A subtle force is initiated in the direction of flexion: the doctor presses the greater wings of the sphenoid and the occiput caudally. The sphenobasilar movement is monitored and allowed to return to a neutral position. The sphenoid and occiput are then gently directed into extension: the doctor draws the greater wings of the sphenoid and occiput towards the cranial vertex.

Various movements can be applied to help correct for restrictions or imbalances discovered during testing. One of the most effective techniques is the "indirect technique" which involves maintaining the cranial mechanism in its position of least restriction (and greatest movement) as the cranium "relaxes". As rebalancing occurs, there will often be a softening, a "relaxing sensation," and a warmth noticed in the tissues

RIGHT AND LEFT TORSION

Maintaining the same contacts as used in the flexion/extension technique, the right greater sphenoid is directed caudally while the left great wing of the sphenoid is directed superiorly. Simultaneously, the right occiput will be directed superiorly while the left occiput is directed caudally. The movements are then reversed. This movement creates a torsion force directed at the sphenobasilar junction. A right torsion would mean that the right sphenoid was high in relationship to the left.

SIDE-BENDING ROTATION

Side-bending rotation in the sphenobasilar joint occurs when there is an approximation between the greater wing of the sphenoid and the occiput causing the cranium to rotate superiorly on that side (essentially, the greater wing and occiput rises on the side of their approximation). Conversely, on the opposite side, there is a lengthening, a spreading apart, with a consequent convexity or bulging of the skull. This is accompanied by an inferior rotation of the cranium on that side. This side-bending disturbance of the sphenobasilar junction is named according to the side of the convexity. Flexion/extension, torsion and side-bending distortions of the sphenobasilar junction are considered to be within physiological constraints of stress to the meninges and associated cranial structures. Lateral and vertical strains, as well as sphenobasilar compression, which are often caused by trauma, are considered to be more serious lesions.

VERTICAL STRAIN

In testing for a vertical strain, the occiput is first directed into extension while Simultaneously directing the sphenoid into flexion. This is done by first directing the greater wings of the sphenoid caudally while simultaneously directing the occiput superior/anteriorly (towards the examiner). The opposite movements are then applied and monitored accordingly.

LATERAL STRAIN

Testing for a lateral strain involves the practitioner's awareness of the axis of rotation at both the sphenoid body and the foramen magnum of the occiput. While testing for a lateral strain, the occiput and the ipsilateral sphenoid are both directed anteriorly while opposing lateral forces are applied. In correcting for lateral strain on the right, for example, both thumbs are placed on the greater wings of the sphenoid with the fingers contacting the lateral borders of the occiput. The right thumb and fingers direct both the sphenoid and occiput anteriorly while concurrently, the right thumb presses the greater wing to the left. Simultaneously the left thumb and fingers direct the sphenoid and occiput posteriorly while concurrently the left fingers direct the left side of the occiput towards the right. Any obliquity of the sphenobasilar junction can then be appreciated. Movement should be equal bilaterally.

SPHENOBASILAR COMPRESSION

Sphenobasilar compression is determined by an overall restriction to movement throughout the cranium. To release A/P sphenobasilar compression, the doctor, contacting the greater wings of the sphenoid and occiput, attempts to draw them apart. As this gentle traction is maintained, an unwinding and releasing of the sphenobasilar symphysis and its associated structures will generally occur.

Dr. Upledger, in his book Craniosacral Therapy, presented a method of releasing compression between the petrous portions of the temporal bones. He called the technique "Lateral Cranial Base Compression" which involves a direct separation of the temporal bones by contacting the pinna of each ear. The pinna of the ears are grasped and a gentle, lateral traction is applied along the direction of the petrous portions. As this traction is maintained, a releasing and an expansion will be felt in a lateral axis. When it is difficult for the doctor to maintain a constant contact of the pinna of the ear, one finger directed into the external acoustic meatus, with the other fingers simultaneously contacting the base of the ear, is often an effective alternative.

Since much of the osteopathic research refers to cranial distortions in terms of these sphenobasilar strain patterns, it is essential that the Sacro-Occipital Technique practitioner become conversant with these terms in order to better understand the existing literature.

For a more detailed explanation of this topic please see:

Blum, CL, Curl, DD, “The Relationship Between Sacro-Occipital Technique and Sphenobasilar Balance. Part One: the Key Continuities,” Chiropractic Technique, Aug 1998, Vol. 10, No. 3, Pp. 95-100.

Blum, CL, Curl, DD, “The Relationship Between Sacro-Occipital Technique and Sphenobasilar Balance. Part Two: Sphenobasilar Strain Stacking,,” Chiropractic Technique, Aug 1998; 10(3): 101-107.

Return to dural connection Articles