Cranial osteopathy

The craniosacral technique was established by Dr. William G. Sutherland in the 1940s. He reasoned that cranial sutures in relation to the skull have their own mobility. After years of study, research, and manipulation, he concluded that the cranial bones, sacrum, dural membranes, and cerebrospinal fluid function as interrelated units. He termed this unit the primary respiratory mechanism. Osteopathic treatment using articulatory techniques aims to restore the cranial rhythmic impulse to a normal rate.

• Cranial bones
  • Midline bones
    • Sphenoid, occiput, ethmoid, and vomer bones
    • Function: flexion and extension
  • Paired bones
    • Remaining cranial bones (e.g., parietal, temporal, frontal)
    • Function: external and internal rotation
• Meninges
  • Three layers of connective tissue that cover and protect the brain and the spinal cord
  • Divided into (from outer to inner layer): dura mater, arachnoid mater, and pia mater
  • Dura mater
    • Continues down the spinal canal and attaches to the S2 vertebra
    • Dural attachments: C2, C3, foramen magnum and the sacrum
    • Folds to form septae: the falx cerebri, falx cerebelli, and tentorium cerebell
• Ventricular system
  • Involved in the production and circulation of cerebrospinal fluid (CSF)
  • CSF is produced by the choroid plexus and reabsorbed in the arachnoid granulations.
• For more information, see “Skull,” “The cerebral cortex, meninges, basal ganglia, and ventricular system,” and “Cranial nerve palsies” articles.
  

The primary respiratory mechanism is a physiological unit comprising the central nervous system (CNS), cerebrospinal fluid (CSF), dural membranes, cranial bones, and sacrum, functioning collectively to control and regulate essential bodily functions such as respiration, circulation, digestion, and elimination.

Components

The primary respiratory mechanism (PRM) is composed of five elements.

1. Inherent motility of the brain and spinal cord
   • The brain and spinal cord have an inherent, wave-like motion.
   • Described as the coiling and uncoiling of the CNS
2. Fluctuation of the CSF: the movement of CSF changes according to the cranial rhythmic movement (PRM)
3. Mobility of the intracranial and intraspinal membranes
   • The meninges surround the CNS and are made up of the dura, arachnoid, and pia mater.
   • The reciprocal tension membrane (RTM) is a continuous connection present from the foramen magnum to the cervical vertebrae and second sacral segment.
     • Formed by the falx cerebri, tentorium cerebelli, and spinal dura
     • These membranes move due to the inherent motility of the brain and spinal cord and fluctuations of the CSF.
     • Motion of these membranes causes the cranial bones and sacrum to move in relation to each other.
4. Articular mobility of cranial bones
   • Although cranial sutures fuse shortly after birth, they contain small motions that cannot be felt individually.
   • An amalgamation of the cranial bones and multiple sutures allows for palpable motion.
   • Cranial rhythmic impulse (CRI)
     • Refers to the palpatory sensation of the widening and narrowing of the skull that reflects the pulsation of the CSF.
     • Normal rate: 10–14 times per minute
5. Involuntary mobility of the sacrum between the ilia
   • The movement of the brain, spinal cord, and CSF causes the RTM to move.
   • Any motion of the RTM causes the sacrum to move
   • The bones move in rhythm with the motion of the shifting tensions of the RTM.

Physiologic motion of the PRM

• The physiologic cranial motion occurs at the sphenobasilar synchondrosis (the articulation between the sphenoid and occiput).
  • The sphenobasilar synchondrosis (SBS) moves in a biphasic cycle (flexion and extension) in response to the pull of the reciprocal tension membrane.
  • The movement is influenced by fluctuations in the CSF and the coiling and uncoiling of the CNS.

Flexion and extension occur around the SBS.

Cranial motion

• Physiologic motion
  • Flexion and extension
  • Torsion
  • Sidebending and rotation (SBR)
• Nonphysiologic motion
  • Vertical strain
  • Lateral strain
  • Compression

The sphenobasilar synchondrosis serves as the reference point for describing diagnostic patterns.

Primary SBS movements

SBS strain patterns

Bone and cranial nerve dysfunctions

• The occipitalatlantal (OA) joint, atlantoaxial (AA) joint, and C2 vertebra dysfunctions may cause vagal somatic dysfunction
• Vagal nerve (CN X) dysfunction may cause referred pain and parasympathetic reflexes (e.g., bradycardia, visceral motility dysfunctions)
• Dysfunction of the trigeminal nerve (CN V2) may cause loss of sensation in the ipsilateral midface
• Dysfunction of the temporal bone and the vestibulocochlear nerve (CN VIII) may cause vertigo, tinnitus, or hearing loss
• Condylar compression of the hypoglossal nerve (CN XII) may cause suckling difficulties in the newborn
• Occipitomastoid compression may cause CN IX, CN X, and CN XI dysfunctions
• For more information, see “Cranial nerve palsies” article.

Flexion and extension dysfunctions

• Axis: 2 parallel transverse axes
• Motion: The sphenoid and occiput rotate in opposite directions around the two separate transverse axes.

While flexion and extension are normal physiological movements of the SBS, they can also present as strain patterns.

During craniosacral flexion, the sphenoid seems to be flexed, while in craniosacral extension the sphenoid appears to be extended.

Flexion dysfunction (osteopathy)

• Sphenoid and occiput motion
  • The sphenoid rotates anteriorly and the occiput rotates posteriorly.
  • Cephalad deviation of the sphenobasilar synchondrosis (SBS)
  • The greater wings of the sphenoid and lateral angles of the occiput move caudad.
• Sacral motion: The sacral base moves posteriorly (counternutation)
• Paired bones movement: external rotation
• Cranial diameters
  • Decreased anteroposterior (AP) diameter of the cranium
  • Increased lateral diameter of the cranium
• Vault hold: index and little fingers spread (as paired lateral bones externally rotate) and move caudad

The base of the occiput and the sacrum move in the same direction.

Flexion dysfunction → restricted extension of the SBS.

Extension dysfunction (osteopathy)

• Sphenoid and occiput motion
  • The sphenoid rotates posteriorly and the occiput rotates anteriorly.
  • Caudad deviation of the sphenobasilar synchondrosis (SBS)
  • The greater wings of the sphenoid and lateral angles of the occiput move cephalad.
• Sacral motion: The sacral base moves anteriorly (nutation)
• Paired bones movement: internal rotation
• Cranial diameters
  • Increased AP diameter of the cranium
  • Decreased lateral diameter of the cranium
• Vault hold: index and little fingers narrow (as paired lateral bones internally rotate) and move cephalad

Extension dysfunction → restricted flexion of the SBS.

Torsion (osteopathy)

• Etiology
  • Skull trauma
  • Dental pathologies or procedures (recent dental procedure involving prolonged jaw opening e.g., a root canal or tooth extraction)
  • Improper sleeping posture
• Axis: 1 anterior-posterior (AP) axis (from nasion to opisthion)
• Motion: The sphenoid and occiput rotate in opposite directions.
• Naming convention: named after the greater wing of the sphenoid that is positioned higher

Torsions are named after the greater wing of the sphenoid that is more superior.

One bone rotates clockwise around the axis while the other rotates counter-clockwise.

Left torsion (osteopathy)

• Motion
  • Sphenoid rotates clockwise and the occiput rotates counterclockwise
  • Left greater wing of the sphenoid and right side of the occiput move superiorly
• Vault hold: left index finger is positioned higher than the right and the right little finger is positioned higher than the left

Right torsion (osteopathy)

• Motion
  • Sphenoid rotates counterclockwise and the occiput rotates clockwise
  • Right greater wing of the sphenoid and left side of the occiput move superiorly
• Vault hold: right index finger is positioned higher than the left and the left little finger is positioned higher than the right

Sidebending and rotation (osteopathy)

• Etiology
  • Trauma to the side of the head
  • Improper sleeping posture
• Axis: 2 parallel vertical and 1 anterior-posterior axes
• Motion
  • Sidebending occurs around the two vertical axes, one through the body of the sphenoid and the other through the foramen magnum.
  • Rotation of the sphenoid and occiput occurs in the same direction around the AP axis and opposite directions on the vertical axes.
• Naming convention: named according to the side of convexity of the sidebending motion (relatively inferior) or in which direction the bones rotate on the AP axis
  

Right sidebending and rotation

• Motion: sphenoid and occiput are closer on the left
• Vault hold: right fingers spread (convex) and move caudad, left fingers narrow and move cephalad

Left sidebending and rotation

• Motion: sphenoid and occiput are closer on the right
• Vault hold: left fingers spread (convex) and move caudad, right fingers narrow and move cephalad

Vertical strain (osteopathy)

• Etiology
  • Trauma to the top of the head or below the mouth
  • Dental procedures
  • Head and neck surgery
  • Oral pathologies
  • Improper sleeping postures
• Axis: 2 transverse axes
• Motion: sphenoid and occiput are rotated in the same direction (clockwise or counterclockwise).
• Naming convention: named according to the position of the sphenoid base at the SBS relative to the occiput

Vertical strain patterns are named according to the position of the sphenoid base at the SBS relative to the occiput.

Superior vertical strain

• Motion
  • Sphenoid and occiput are rotated anteriorly (clockwise)
  • The sphenoid base is superior to the occiput at the sphenobasilar synchondrosis.
• Vault hold: : the index fingers move downward and the little fingers move upward

Inferior vertical strain

• Motion
  • Sphenoid and occiput are rotated posteriorly (counterclockwise)
  • The sphenoid base is lower to the occiput at the sphenobasilar synchondrosis.
• Vault hold: the index fingers move upward and the little fingers move downward

Lateral strain (osteopathy)

• Etiology
  • Traumatic force to the side of the head
  • Dental pathologies or procedures
  • Improper sleeping posture
• Axis: 2 parallel vertical axe
• Motion: sphenoid and occiput rotate in the same direction but translate in opposite directions due to shearing forces.
• Naming convention: named according to the position of the sphenoid base at the SBS relative to the occiput (lateral movement or translation of the sphenoid)

Lateral strain patterns are named for the position of the sphenoid base at the SBS relative to the occiput.

Right lateral strain

• Motion: the base of the sphenoid shears right, the greater wing of the sphenoid goes to the left, and the base of the occiput goes to the left
• Vault hold: : parallelogram with the index finger shifting to the left and the little finger shifting to the right

Left lateral strain

• Motion: the base of the sphenoid shears left, the greater wing of the sphenoid goes to the right, and the base of the occiput goes to the right
• Vault hold: parallelogram with the index finger shifting to the right and the little finger shifting to the left

Compression (osteopathy)

• Etiology: SBS compression typically occurs after trauma to the head (e.g., during birth or motor vehicle accident) and would not explain this patient's cranial examination findings.
• Motion: Sphenoid and occiput movement is restricted
• Vault hold: weak flexion and extension or lack of movement
  • Compensatory patterns may be present.
  • Increased internal and external rotation of the paired lateral bones

Diminished or absent cranial rhythmic impulse during extension and flexion of the SBS.

Overview

• Assessment of the sphenobasilar synchondrosis is primarily achieved by palpating the cranium using the vault hold.
• Although there are several variations of the vault hold, the classic technique should be used by students.
• Supplementary techniques allow for palpation of other cranial motions.

Vault hold

• Function: allows for general palpation of the cranial bones
• Position: supine
• Procedure
  1. Place hands on both sides of the cranium.
     • Index fingers: on the greater wing of the sphenoid over the pterion
     • Middle fingers: on the temporal bone, anterior to the ear
     • Ring fingers: on the temporal bone in the mastoid region, posterior to the ear
     • Little fingers: on the occiput
     • Thumbs: gently resting over the superior parietal aspect of the cranium
  2. Palpate the cranial motion through the respiratory cycle.

Frontal-occipital hold

• Function
  • Palpation of the anterior-posterior movement of the cranial bones
  • Asses the PRM.
  • Identify the freedom of motion of the frontal bones and occiput.
• Position: supine
• Procedure
  1. Wrap one hand under the patient's head, along the inion and nuchal line.
  2. Rest the other hand over the frontal bone, middle finger on the glabella, 4^th or 5^th finger over the greater wing of the sphenoid.
  3. Palpate anterior-posterior movement of the cranial motion.

Posterior-occipital hold (Becker hold)

• Function: palpation of the posterior cervical spine and its interaction with the occiput
• Position: supine
• Procedure
  1. Cup the occiput with the palms.
  2. Rest thumbs on the mastoid processes.
     • Alternative placement: rest thumbs on the sphenoid bone (anterior to the ear)
  3. Place the remaining fingers along the posterior aspect of the neck.
  4. Palpate interaction of the occiput with the cervical spine.

Occipital condyle decompression

• Function
  • Decompresses occipital condyles
  • Balances the reciprocal tension at the hypoglossal canal
  • Normalizes the function of cranial nerve XII
• Position: supine with examiner seated at the head of the table and both forearms resting on the table (establishing a fulcrum)
• Procedure
  1. Have the patient's head rest on your palms with the index and middle fingers contacting the condylar processes (as far caudad on the occiput as the soft tissue and C1 allow) on both sides.
  2. Apply a gentle cephalad and lateral traction at the base of the occiput.
  3. Achieve a balanced tension.
  4. Maintain traction until a release is felt.
  5. Reassess.

Condylar compression can affect CN XII, causing sucking difficulties in the newborn.

Venous sinus technique

• Function: decrease venous congestion and improve circulation and drainage of the head through the jugular foramen
• Position: supine with examiner seated at the head of the table
• Procedure
  1. Perform thoracic inlet release and treat any cervical restrictions.
  2. Use finger pads to treat each sinus by spreading the overlying sutures.
     • Occipital sinus: finger pads rest just below the inion (occipital sinus)
     • Transverse sinuses: little fingers rest on the inion (medially) and index fingers rest along nuchal line (laterally)
     • Superior sagittal sinus: starting at lambda, thumbs travel along the sagittal suture until the bregma is reached
  3. Reassess.

Compression of the fourth ventricle (CV4)

• Function: restores normal craniosacral mechanism and increases amplitude of the cranial rhythmic impulse
• Position: supine with examiner seated at the head of the table
• Procedure
  1. Place thenar eminences just below the nuchal line, medial to the mastoid processes.
  2. Apply gentle superomedial traction: exaggerate traction during the exhalation phase.
  3. Hold until a still point is reached.
  4. Reassess.

V spread

• Function: reduces restriction along any cranial suture
• Position: supine with examiner seated at the head of the table
• Procedure
  1. Place two fingers on each side of the restricted suture.
  2. Turn the patient's head to shift weight onto your fingers.
  3. Apply gentle pressure with the opposite hand directly opposite to the affected suture.
  4. Apply a distracting and separating traction with your fingers.
  5. Hold until a release is felt.
  6. Reassess.

Sacral rocking

• Function: improves movement of the sacrum in relation to the primary respiratory mechanism
• Position: prone
• Procedure
  1. Place one palm on the apex and the other on the base and interlock your fingers.
  2. Ask the patient to take deep breaths.
  3. Exaggerate motion of the sacrum through inhalation (counternutation) and exhalation (nutation).
  4. Continue for 4–5 cycles or until motion is improved.
  5. Reassess sacral motion.

Temporal rocking

• Function
  • Restore synchronous motion of the temporal bone
  • Restore function of the cranial nerve VIII
• Position: supine with examiner seated at the head of the table
• Procedure
  1. Support skull in the palms and place thumbs just anterior to the mastoid processes.
  2. Apply posteromedial traction on the inferior aspect of the mastoid processes (introduces external rotation).
  3. Apply a posteromedial compression on the superior aspect of the mastoid process (introduces internal rotation).
  4. Continue rocking motion until motion on each side synchronizes.
  5. Reassess temporal bone motion.

Base spread

• Function: diagnoses and treats tension at the craniocervical junction
• Position: supine with examiner seated at the head of the table
• Procedure
  1. Have the patient's head rest on your palms with the index fingers on the mastoid process (of the temporal bone), middle and ring fingers on either side of the occipitomastoid suture, and little fingers on the occiput and the head slightly flexed.
  2. Apply gentle superior-lateral traction.
     • Index fingers tract more laterally to match the angle of the petrous portion (∼ 45° from midline)
     • Middle and ring fingers tract along the occipital condyles (∼ 30° from midline)
  3. Assess for restriction.
     • Increased resistance along index finger → temporal bone restriction
     • Increased resistance along middle finger → occipital restriction
     • Increased resistance along middle and ring fingers → occipitomastoid restriction
  4. Maintain traction until a balance is achieved along all fingers.
  5. Reassess.

Occipitomastoid suture release

• Function: releases tension on the vagus nerve by releasing restriction at the occipitomastoid suture
• Position: supine with examiner seated at the head of the table
• Procedure
  1. Cup the occiput with the contralateral palm with the fingertips just medial to the occipitomastoid suture.
  2. Grasp the mastoid process with the thumb and index fingers of the ipsilateral hand just lateral to the occipitomastoid suture.
  3. Evaluate motion of the suture by gently separating the left and right fingers without sliding over the skin.
  4. Move fingers in opposite directions until a release is felt.
  5. Reassess.