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Clinical Practice  |   January 2020
Taxonomy of the Lateral Strain Patterns at the Sphenobasilar Synchondrosis for Osteopathic Cranial Manipulative Medicine
Author Notes
  • From the Department of Osteopathic Manipulative Medicine at the New York Institute of Technology College of Osteopathic Medicine in Old Westbury. 
  • Financial Disclosures: None reported. 
  • Support: None reported. 
  •  *Address correspondence to John D. Capobianco, DO, 9 Huron St, Glen Head, NY 11545-1001. Email: johncapo@aol.com
     
Article Information
Neuromusculoskeletal Disorders
Clinical Practice   |   January 2020
Taxonomy of the Lateral Strain Patterns at the Sphenobasilar Synchondrosis for Osteopathic Cranial Manipulative Medicine
The Journal of the American Osteopathic Association, January 2020, Vol. 120, 25-29. doi:https://doi.org/10.7556/jaoa.2020.009
The Journal of the American Osteopathic Association, January 2020, Vol. 120, 25-29. doi:https://doi.org/10.7556/jaoa.2020.009
Web of Science® Times Cited: 1
Abstract

Lateral strain is a type of nonphysiologic cranial dysfunction that occurs at the sphenobasilar synchondrosis. In this dysfunction, the sphenoid and occiput rotate in the same directions along 2 vertical axes. There is currently no consensus on the nomenclature for this cranial dysfunction. In this article, the authors provide a standard nomenclature for lateral strains using the historical writings of pioneers in osteopathic medicine, including William Gardner Sutherland, DO, Anne L. Wales, DO, and Harold Magoun, DO. The authors establish the following consensus: (1) Lateral strains are named for the side to which the basisphenoid shifts; (2) The more prominent greater wing of the sphenoid is on the same side to which the basisphenoid shifts; (3) In vault and fronto-occipital holds, the holds form a parallelogram shape, with the index fingers pointing to the same side as the more prominent greater wing; and (4) The hand that is on the side of the prominent greater wing will shift anteriorly while the hand on the opposite side will shift posteriorly.

Major cranial dysfunctions result from abnormal movement of the sphenoid and occiput at the sphenobasilar synchondrosis (SBS). Although individual cranial bone dysfunctions occur, the vast majority of the remainder of the cranial bones’ movement and their corresponding nomenclature occur in relation to the actions at these 2 midline bones. Although most cranial strain patterns have a defined and well-understood nomenclature, there is much confusion about the taxonomy of the lateral strain pattern. The purpose of this article is to describe the lateral strain as it has traditionally been presented in the writings of William Gardner Sutherland, DO, and his students to standardize the taxonomy of this cranial dysfunction for today's osteopathic physicians. 
There are 2 types of cranial dysfunctions at the SBS: physiologic and nonphysiologic. The more physiologic cranial dysfunctions are flexion, extension, torsion, or sidebending/rotation at the SBS. Physiologic dysfunctions can occur from total bodily compensations, such as a continuation of a general scoliosis of the spine—in the context of viewing the cranial bones as craniobrae,1 or “modified vertebrae,” a descriptor used by Sutherland in a collection of his writings.2 Nonphysiologic SBS dysfunction usually results from severe trauma or compression. The types of nonphysiologic dysfunctions are lateral strains, vertical shears, and SBS compression. These more pathologic dysfunctions usually have movement about axes in the same direction, with a superimposed shearing component that has no axis or a compression aspect that essentially prevents the mobility of the cranial bones. These dysfunctions can usually be diagnosed through active motion testing of the patient's cranium either with the vault hold or the fronto-occipital hold, as both techniques have the operator's fingers on the occiput and sphenoid or portions thereof.3 
Lateral strains are named for the side of the directional shift of the basisphenoid, which is also the side of the more prominent greater wing of the sphenoid. In a vault hold, after active motion testing in all planes of rotation, the hands will form a parallelogram shape, with the index fingers of both hands pointing toward the side where the basisphenoid has shifted in the transverse plane and the fifth fingers of both hands pointing away. For a right lateral strain, there will also be a slight anterior glide of the right hand and a slight posterior glide of the left hand. The opposite will occur with a left lateral strain. Both lateral and anterior movement caused by shearing and rotation of axes create the geometry of a parallelogram. 
Lateral strains are a type of nonphysiologic cranial dysfunction in which the sphenoid and occiput rotate around 2 vertical axes that go through the sphenoid and foramen magnum, in the same directions.4 Lateral strains commonly result from counter-physiologic movement often caused by injury. This trauma usually involves a shearing force that induces rotation of the sphenoid and occiput in the same direction about their vertical axes. Specifically, force applied to the sphenoid bone is transmitted to the basisphenoid and is manifested to the operator's hands as one of the greater wings of the sphenoid shifting laterally and anteriorly. Summed up, lateral strains should be named for the side toward which the basisphenoid is shifted, which will also be the side of the more prominent greater wing. After active motion testing in vault or fronto-occipital holds, the parallelogram hand formation, with the more prominent greater wing of the sphenoid being indicated by the side toward which both index fingers shift toward and also the side of the more anterior hand, should be performed. For instance, if in vault or fronto-occipital hold the index fingers point toward the right and the right hand is more anterior than the left, then the right greater wing is more prominent, meaning that the basisphenoid is shifted toward the right side. The nomenclature for this example would be a right lateral strain. 
Trauma or injury that can cause lateral strains may occur in utero, during delivery, or from a direct hit to the cranium. Crowding in utero or during delivery may cause the sphenoid to shift laterally from a force coming from one anterolateral quadrant to the opposite posterolateral quadrant, which results in the parallelogram deformity typically found in lateral strains. A direct hit, such as a punch to the left pterion, which includes the sphenoid, will induce a right lateral strain and vice versa. Finally, trauma to the occiput or to the hemiocciput may induce a displacement of this bone in relation to the sphenoid, as the naming of the dysfunction is for the latter.5 
Understanding how lateral strains are named and the hand motions associated with diagnosing lateral strains in the vault and fronto-occipital hold has recently been a topic of controversy in the osteopathic medical community. While the other cranial dysfunctions have a standardized set of rules for nomenclature and diagnosis, the taxonomy of lateral strains has varied between sources. Some of the most commonly used osteopathic textbooks—Foundations in Osteopathic Medicine,6 Atlas of Osteopathic Techniques,3 and An Osteopathic Approach to Diagnosis and Treatment,7 can be said to rightfully walk past the issue of laterality in lateral strains in terms of sidedness (right or left). The third edition of Foundations in Osteopathic Medicine6 states that lateral strains are named for the direction in which the basisphenoid shifts. However, there is no mention of how the greater wings of the sphenoid move in relation to the basisphenoid or how the hands should move with either the vault or the fronto-occipital hold to properly diagnose the lateral strain.6 In Atlas of Osteopathic Techniques,3 lateral strains are once again described to be named for the direction in which the basisphenoid shifts relative to the occiput and the parallelogram movement the hands will take in vault hold. Nevertheless, there is no mention of which direction the hand parallelogram shifts based on the basisphenoid position or a description that the hand on the side of the greater wing of the sphenoid will shift slightly anteriorly.3 In An Osteopathic Approach to Diagnosis and Treatment,7 there is mention of the parallelogram shape of the hands for a lateral strain; however, it is not mentioned how lateral strains are named, what hand motions will be used in vault hold, or the anterior motion of the hand on the side of the prominent greater wing.8 
Because these osteopathic medical textbooks tackle osteopathic cranial manipulative medicine (OCMM) (the 3rd edition of Foundations in Osteopathic Medicine6 and An Osteopathic Approach to Diagnosis and Treatment7 still use the term osteopathy in the cranial field, but the current Glossary of Osteopathic Terminology9 uses OCMM), we believe reproposing the historical nomenclature of the observations of Sutherland and his students would only add to a fuller understanding of the description of the naming and diagnosis of lateral strains. There is no current consensus on this topic, which can be frustrating to students and those in the trenches of academia. Confusion over basic cranial strain patterns would be similar to that of omitting certain planes of motion and axes for basic spinal and sacral somatic dysfunction. With this article, we aimed to provide classic standard nomenclature using the historical writings of pioneers in osteopathic medicine, including Dr Sutherland, Anne L. Wales, DO, and Harold Magoun, DO, and to standardize the taxonomy of these particular strains at the cranial base as put forth by historically notable osteopathic physicians to current and future generations of osteopathic physicians. 
Proving Our Thesis
Dr Sutherland was a student of Andrew Taylor Still, MD, DO, the founder of osteopathy. It should be noted that Sutherland attributes the cranial concept as a continuation of Still's teachings. We found 4 of the 5 phenomena in the original writings of Still. An article on all 5 phenomena is beyond the scope of this article but may be the subject of a future publication. 
In his work, The Cranial Bowl,10 Sutherland discusses his methods of diagnosing cranial dysfunctions, in which the greater wings of the sphenoid must be palpated to compare which wing is felt to be more prominent because the more prominent greater wing indicates the sphenoid's position at the basilar region. Since lateral dysfunctions are named for where the basisphenoid shifts, based on Sutherland's teachings, we can use the more prominent greater wing to identify the direction in which the basisphenoid has shifted and, therefore, how the dysfunction should be named. For example, when there is a more prominent right greater wing of the sphenoid, then the basisphenoid would therefore be shifted to the right, which would make this a right lateral strain. 
Dr Wales, a student of Sutherland's, was another historical figure in the osteopathic medical profession. In a signed letter to the first author of this article, Wales explained her findings and understanding of cranial dysfunctions, all of which further supported Sutherland's explanation in The Cranial Bowl.10 Wales stated that lateral strain patterns are named at the sphenobasilar synchondrosis with “the greater wing to the right” or “with the greater wing to the left” based on the position of the basisphenoid. From Wales and Sutherland, we can conclude that the greater wings of the sphenoid will be more prominent on the side that the basisphenoid shifts toward (A.L. Wales, written communication, January 1999). In Sutherland's book, Teachings in the Science of Osteopathy—which was published nearly a half a century after his death, edited by Wales—it is stated that the basilar portions of the sphenoid and occiput at the SBS will be in opposite directions because the sphenoid and occiput themselves rotate in the same directions. Since we are naming the lateral strain according to the direction of the base of the sphenoid, we stick to the conventional wisdom that in a right lateral strain, the base of the occiput will be directed toward the left.11 
In his magnus opus, Osteopathy in the Cranial Field,5 Magoun systemically organizes and explains the work of his mentor, Dr Sutherland. This textbook has been one of the most prominent and comprehensive pieces of literature for the student of osteopathic medicine, which discusses Still's “highest known element” (cerebrospinal fluid) and osteopathy above the neck in general. Magoun brings into consideration the anterior positioning of the cranium in a lateral strain. With a lateral strain, the 2 quadrants of the sphenoid will become asymmetric, with one becoming more anterior and the other becoming more posterior with relation to each other. In addition, since the sphenoid and occiput rotate in the same directions about 2 vertical axes in a lateral strain, the occiput will also be carried anteriorly on the same side as the anterior sphenoid. The side with the more anterior quadrant will designate the side to which the basisphenoid is carried laterally. Therefore, in a right lateral strain, the basisphenoid will shift to the right, the right sphenoid and right occiput will shift anteriorly, and the left sphenoid and left occiput will shift posteriorly. When diagnosing using palpation, the vault hold for a right lateral strain will have the physician's hands shift in a parallelogram toward the right side, with the right hand moving anteriorly and the left hand moving posteriorly. The reason for this is because when the basisphenoid shifts to the right, the right greater wing is more prominent, which is the cause of the right-shifted parallelogram. The anterior motion of the right hand and posterior motion of the left hand is from the ipsilateral sphenoid and occiput shifting anteriorly and the contralateral side shifting posteriorly in relation to the SBS.5 The summation of a lateral strain is not only displacement in the horizontal plane due to the shearing force but also movement anteriorly due to the rotation about 2 vertical axes. 
Current textbooks lend the traditional explanation of the lateral strain in the works of Sutherland, Wales, and Magoun. In Exploring Osteopathy in the Cranial Field,12 it is stated that lateral strains are named for the side of the shift of the basisphenoid, which is perceived by palpation of the more prominent greater wing, further suggesting that the prominent greater wing and shifted basisphenoid are on the same side—that is to say that the sphenoid on the ipsilateral side of the lateral basisphenoid is anterior, with the occiput of that side also anterior, further supporting Magoun's treatise. It goes without restating that the basisphenoid and basiocciput move in opposite directions because these structures obey rotation in opposite directions on transverse axes in the physiologic state. So in a left lateral strain, the basisphenoid is shifted left and basiocciput is shifted right. 
Based on the works cited above, the following approach should be strongly considered with respect to diagnosing and naming lateral strains: 
  • ■ Lateral strains must be named for the side toward which the basisphenoid shifts.
  • ■ The greater wing of the sphenoid will be more prominent on the side toward which the basisphenoid shifts.
  • ■ The sphenoid and occiput on the ipsilateral side of the shifted basisphenoid will move anteriorly, whereas, the contralateral sphenoid and occiput will move posteriorly.
  • ■ The fingers of the operator's hands will form a parallelogram in which both index fingers will move toward the side of the shifted basisphenoid (also more prominent greater wing) and both fifth fingers will move to the opposite side.
  • ■ The hand on the side of the shifted basisphenoid (also the more prominent greater wing) will move anteriorly and the hand on the opposite side will move posteriorly.
The following quote from Magoun summarizes this article's approach to lateral strains: “Vault approach. With the appropriate hand position, lateral strain or displacement is initiated by starting rotation of both sphenoid and occiput in the same direction on their vertical axes. Wait for the mechanism to carry on. If testing for a lateral shift with the sphenoid to the right, the greater wing area and the lateral angle of the occiput are carried anteriorly on that side with the index and little fingers of one hand while the other hand is moving the left side posteriorly. The basisphenoid swings to the side that is carried anteriorly and the basiocciput swings to the side that is carried posteriorly.”5(p 134) 
For further clarity, here are guidelines that should be used in a specific example of a right lateral strain: 
  • ■ Basisphenoid will be shifted to the right.
  • ■ Right greater wing will be more prominent by palpation.
  • ■ Right sphenoid and occiput will move anteriorly, and left sphenoid and occiput will move posteriorly.
  • ■ The hands will form a parallelogram, with the index fingers pointed to the right and the fifth fingers pointed to the left.
  • ■ In vault or fronto-occipital hold, the right hand will move anteriorly and the left hand, posteriorly, preserving the necessary geometry of a parallelogram.
We anticipate that this article will bring clarity to the issue of lateral strains from Dr Sutherland and his dedicated cohort of student preservationists. Setting a standard for osteopathic physicians to use uniform and coherent taxonomy of somatic dysfunction of the cranium will only further osteopathic medical science for the benefit of those who have traumatic brain injury, migraine, or even the occasional muscle tension headache. These conditions affect lifestyle, employment, and relationships, making the diagnosis and management of cranial dysfunctions an important step to providing the most optimal patient care. 
Conclusion
Although the diagnosis and nomenclature of lateral strains has been a topic of diverse discussion and uncertainty in both the laboratory and podium for the student of osteopathic medicine, we sought to draw a consensus with this article. By exploring the works of the students of A.T. Still, we hope that osteopathic physicians will finally be in solidarity when it comes to the taxonomy of this dysfunction. 
References
Weaver CW, Sorrel M. Charlotte Weaver: Pioneer in Cranial Osteopathy. Indianapolis, IN: The Cranial Academy; 2010.
Sutherland WG, Sutherland AS, Wales AL. Contributions of Thought: The Collected Writings of William Garner Sutherland, D.O., Pertaining to the Art and Science of Osteopathy Including the Cranial Concept in Osteopathy Covering the Years 1914-1954. Portland, OR: Ruda Press; 1998.
Nichols AS, Nichols EA. Osteopathic cranial manipulative medicine. In: Nicholas NS, ed. Atlas of Osteopathic Techniques. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2016.
Rivera-Martinez S, Wells MR, Capobianco JD. A retrospective study of cranial strain patterns in patients with idiopathic Parkinson's disease. J Am Osteopathic Assoc. 2002;102(8):417-422.
Magoun HI. Osteopathy in the Cranial Field. Indianapolis, IN: Cranial Academy; 2011.
King HH. Osteopathy in the cranial field. In: Chila A, executive editor. Foundations of Osteopathic Medicine. 3rd ed. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2011.
Ettlinger, H, Gintis, B. Cranial motions and dysfunctions. In: DiGiovanna EL, Schiowitz S, Dowling DJ. An Osteopathic Approach to Diagnosis and Treatment. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.
Ettlinger H, Gintis B. Cranial osteopathy. In: DiGiovanna EL, Schiowitz S, Dowling DJ, eds. An Osteopathic Approach to Diagnosis and Treatment. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.
Glossary of osteopathic terminology. American Association of Colleges of Osteopathic Medicine website. https://www.aacom.org/docs/default-source/insideome/got2011ed.pdf. Accessed November 19, 2019.
Sutherland WG. The Cranial Bowl. Free Press Company; 1994.
Wales A, Sutherland WG. Teachings in the Science of Osteopathy. Portland, OR: Sutherland Cranial Teaching Foundation; 2003.
Hruby RJ. Exploring Osteopathy in the Cranial Field. 2nd ed. Baltimore, MD: Raymond J. Hruby; 2013:148.