Sacro-Occipital Technique (SOT) is a system of chiropractic analysis and correction developed by Major Bertrand DeJarnette that establishes a structure for diagnosis and treatment based upon three identifiable and interrelated systems of body reaction. 1.2 Developed by Major Bertrand DeJarnette, who was both a chiropractor and an osteopath, the method originated from concepts he began forming in the 1920s, a period of significant diversification in chiropractic methods as documented in historical texts such as David D. In 1967, the Palmer College of Chiropractic published the book Three Generations: A History of Chiropractic. 3. DeJarnette formally established the Sacro Occipital Research Society in 1929 to further investigate and teach his developing procedures 1. The technique is distinguished by its use of padded wedges, known as pelvic blocks, which are placed strategically under the pelvis to allow gravity and the patient's own respiratory motion to facilitate correction.
The theoretical foundation of SOT posits that the sacrum and occiput are connected through the dural-meningeal system, a continuous sheath of connective tissue that encases the spinal cord and brain. Movement or misalignment of the sacrum is believed to transmit tension through this system to the occiput, potentially affecting neurological function and the circulation of cerebrospinal fluid (CSF). A central concept is the Sacro-Occipital pump mechanism, which is theorized to be integral to the Primary Cranial Sacral Respiratory Mechanism. This mechanism involves the subtle, rhythmic respiratory motion of the cranium and sacrum, which is thought to influence CSF flow and the overall function of the central nervous system 4. SOT procedures aim to restore the normal function of this pump mechanism.
Diagnosis in SOT involves a system of indicators that classify a patient's condition into one of three primary categories. These categories guide the specific placement of the pelvic blocks and the overall treatment protocol. Diagnostic indicators include postural analysis, reflex points, and specific patterns of muscle weakness. One such diagnostic procedure, the Arm-Fossa Test, was the subject of a 2015 pilot study by Cooperstein et al. which assessed its consistency with the Gillet test for sacroiliac joint fixation; the preliminary data were consistent with a potential relationship but did not definitively establish a correlation 5. Based on the category determination, practitioners use the blocks to address pelvic and sacral torsions and misalignments. For example, a 2006 case series by J.I. Hochman, published in the Journal of Manipulative and Physiological Therapeutics, investigated the application of SOT Category II blocking procedures on five subjects with diagnosed sacroiliac instability. The study found that the procedures produced a measurable increase in lumbar spine range of motion in all planes except for extension 6. DeJarnette codified his life's work in his comprehensive text, "Sacro Occipital Technic," which was published in 1984, providing a definitive reference for the system he had spent decades developing 7.
Definition and core principles
Sacro-Occipital Technique, commonly known as SOT, is a system of chiropractic analysis and treatment developed by Major Bertrand DeJarnette, who held degrees in both chiropractic and osteopathy. DeJarnette began formulating his concepts in the 1920s and formally established the Sacro Occipital Research Society International (SORSI) in 1929 to further the research and teaching of his methods 1. The fundamental premise of SOT is the existence of a reciprocal functional relationship between the sacrum, located at the base of the spine, and the occiput, the bone at the base of the skull. This relationship is considered integral to the normal function of the central nervous system.
The technique's theoretical foundation is linked to the Primary Cranial Sacral Respiratory Mechanism, a concept originating in osteopathy. This mechanism posits an inherent, rhythmic motion of the cranial bones and the sacrum, which in turn influences the fluctuation of cerebrospinal fluid (CSF) and the tension within the dural membranes 4. SOT proposes that the sacrum's subtle respiratory motion between the iliac bones acts as a "Sacro-Occipital pump." This pump is theorized to be a primary driver for the circulation of CSF from the sacral canal up the spine to the ventricular system of the brain, thereby affecting neurological health 4.
Diagnosis within the SOT framework is centered on classifying sacroiliac joint dysfunction into three distinct patterns, known as categories. This categorization system directs the therapeutic protocol, which often involves the use of wedge-shaped pelvic blocks placed under the patient. Category I represents the foundational and most common form of dysfunction. It is defined as a primary respiratory issue where the sacroiliac joints lose their normal, synchronized motion during the respiratory cycle. This fixation is believed to directly impair the Sacro-Occipital pump mechanism, leading to dural tension and altered CSF flow 4. The therapeutic goal for a Category I patient is to restore the normal respiratory motion of the sacroiliac articulation.
Category II involves a failure of the weight-bearing, ligamentous portion of the sacroiliac joint, resulting in hypermobility or instability. Unlike the respiratory fixation of Category I, a Category II subluxation is characterized by a physical separation of the joint surfaces, indicating a compromise of the joint's structural integrity. This instability creates a dysfunctional pelvic foundation, which can lead to compensatory changes throughout the spine and nervous system. Treatment for Category II focuses on stabilizing the hypermobile joint and correcting the resulting pelvic imbalance.
Category III dysfunction is defined by a primary lumbar intervertebral disc pathology that causes nerve root compression or irritation, often presenting as sciatica. In this scenario, the observed pelvic torsion and sacroiliac misalignment are considered a secondary, antalgic (pain-avoiding) posture adopted by the body in response to the disc lesion. SOT protocols for Category III aim to reduce pressure on the affected nerve root and address the underlying disc issue. The differentiation between these categories relies on a specific set of clinical indicators, including the Arm-Fossa Test. A 2015 pilot study by Cooperstein et al. that assessed the consistency between the Arm-Fossa Test and the more conventional Gillet test for sacroiliac fixation noted that its preliminary data was consistent with a potential relationship, though it did not statistically establish a firm correlation 5.
Historical development
The origins of Sacro-Occipital Technique (SOT) are rooted in the clinical research and synthesis of its founder, Major Bertrand DeJarnette, a doctor of chiropractic and osteopathy 1. DeJarnette, who initially trained as an engineer, brought a biomechanical perspective to his clinical work after graduating from the Nebraska College of Chiropractic. His development of SOT began in the 1920s as he sought to create a system that moved beyond simple spinal adjustments to address the broader functional relationship between the sacrum and the occiput 1. His dual professional training informed an approach that integrated structural and physiological principles, a perspective that was distinct within the chiropractic profession of that era 8.
To formalize his research and create a platform for teaching his evolving methods, DeJarnette established the Sacro Occipital Research Society (SORS) in 1929 1. SORS became the primary vehicle for disseminating SOT through seminars and publications for decades. DeJarnette's foundational theory posited a "Sacro-Occipital pump" mechanism, a concept that linked the respiratory motion of the cranium and sacrum 4. This action was theorized to be essential for the proper circulation of cerebrospinal fluid (CSF), with disruptions to this mechanism potentially affecting the health of the entire nervous system 4. This focus on CSF dynamics and cranial motion reflected an osteopathic influence not commonly found in mainstream chiropractic techniques of the time, as documented in general histories of the profession 3.9
Throughout the mid-20th century, DeJarnette continued to refine his system, developing the three-category system of classification, specific pelvic blocking procedures, and cranial and visceral techniques. His work was disseminated primarily through seminars and a series of manuals. This lifetime of work culminated in the publication of his comprehensive text, "Sacro Occipital Technic," in 1984, which organized his procedures and theories into a cohesive reference 7. The clinical protocols he developed continued to be practiced and investigated long after their initial formulation. For example, the SOT Category II blocking procedure, designed to address sacroiliac joint hypermobility, was the subject of a 2006 case series published in the Journal of Manipulative and Physiological Therapeutics. This investigation by Hochman on five subjects with sacroiliac instability found that the SOT protocol produced measurable increases in lumbar spine range of motion in all planes except for extension, demonstrating continued clinical and academic interest in the historical methods established by DeJarnette 6.
Theoretical basis and mechanism of action
The foundation of Sacro-Occipital Technique rests upon a model that extends beyond localized spinal biomechanics to include a theorized systemic physiological process. Its central construct is the Primary Cranial Sacral Respiratory Mechanism (PCSRM), a concept first articulated in cranial osteopathy and integrated into chiropractic by SOT’s founder, Major Bertrand DeJarnette, himself a chiropractor and osteopath 1. This model proposes an inherent, subtle, and rhythmic motion within the craniosacral system that is distinct from thoracic breathing or cardiac rhythm. The PCSRM is described as comprising five elements: the inherent motility of the brain and spinal cord, the fluctuation of cerebrospinal fluid (CSF), the mobility of the intracranial and intraspinal dural membranes, the articular mobility of the cranial bones, and the involuntary mobility of the sacrum between the ilia 4. According to this framework, dysfunction in any part of this integrated system can precipitate wide-ranging physiological consequences.
The primary mechanism of action proposed for SOT interventions, especially the use of pelvic blocks, is the "sacro-occipital pump" 4. In practice, precisely placed wedges or blocks under the pelvis utilize the patient's body weight and respiratory movements to induce a gentle, passive motion in the sacrum and pelvis. This motion is not arbitrary; it is intended to correct specific biomechanical patterns identified through SOT's categorical analysis. The theory posits that the rhythmic movement of the sacrum is transmitted superiorly to the occiput via the dural membrane system, which acts as a "reciprocal tension membrane" connecting the two poles of the spine 4. This process, explained in standard chiropractic texts like Textbook of chiropractic technique, aims to restore normal, synchronous motion between the sacrum and the cranium.
The intended physiological result of activating the sacro-occipital pump is the normalization of cerebrospinal fluid circulation 4. The CSF environment is integral to the metabolic support and mechanical protection of the central nervous system. SOT theory postulates that disruptions to the PCSRM, such as dural tension or restrictions in sacral or cranial motion, can impede the normal, rhythmic circulation of CSF. By restoring the inherent motion of the craniosacral system, the pump mechanism is believed to enhance the circulation, drainage, and homeostatic balance of the CSF, which is in turn hypothesized to improve neurological function 4.
Clinical application of this model relies on a system of diagnostic indicators to assess the craniosacral system's status. One such procedure is the Arm-Fossa Test, used by practitioners to evaluate sacroiliac joint function. The scientific validation of these unique diagnostic tests is an ongoing area of inquiry. For example, a 2015 pilot study by Cooperstein et al. examined the consistency between the Arm-Fossa Test and the established orthopedic Gillet test for sacroiliac motion 5. The preliminary data was found to be consistent with a potential correlation between the two tests, but the results were not statistically robust enough to formally establish this relationship 5. This research represents an effort to connect the complex theoretical constructs of SOT with objective, measurable clinical findings.
Diagnostic procedures and pelvic blocking
Beyond individual tests, the core of SOT diagnosis is the classification of a patient's condition into one of three primary categories, a system developed by Major Bertrand DeJarnette, a chiropractor and osteopath, beginning in the 1920s 1. This classification dictates the therapeutic approach, particularly the placement of wedge-shaped pelvic blocks, with the complete methodology detailed in DeJarnette's 1984 text, "Sacro Occipital Technic" 7. The blocks are padded wedges placed under the pelvis of a prone patient, using the patient's own body weight and respiration to facilitate a slow, gentle correction.
Category I addresses a primary dysfunction of the dural-meningeal system and its relationship between the sacrum and the occiput. The central theory posits that a Category I condition disrupts the Sacro-Occipital pump, a mechanism that supports the Primary Cranial Sacral Respiratory Mechanism 4. This system's function is considered essential for the rhythmic circulation of cerebrospinal fluid (CSF) around the brain and spinal cord 4. Diagnostic indicators for Category I are intended to reveal signs of dural tension. The corresponding blocking procedure involves placing two blocks under the pelvis, typically beneath the anterior superior iliac spines (ASIS), to use gravity and respiratory motion to help restore the theorized pumping action.
Category II involves instability or hypermobility of the sacroiliac joint, presenting with different diagnostic indicators that point toward a weight-bearing imbalance in the sacroiliac articulation. The corrective blocking procedure for a Category II patient is specific, involving the placement of one block under the ASIS of the dysfunctional side and the other under the opposite ischial tuberosity. This cross-wise configuration is designed to apply a gentle torque to the pelvic girdle to help stabilize the hypermobile joint. The clinical effect of this procedure was the subject of a 2006 case series by Hochman published in the Journal of Manipulative and Physiological Therapeutics. The study, which involved five subjects with diagnosed sacroiliac instability, found that SOT Category II blocking produced a measurable increase in lumbar spine range of motion in all planes except for extension 6.
Category III is identified by indicators of acute lumbar disc pathology, frequently involving nerve root compression and sciatica. It is considered a failure of the body's ability to compensate for pelvic and spinal stress. The blocking procedure is intended to reduce mechanical pressure on the affected lumbar disc. This is typically achieved by placing the blocks to create a specific angle of pelvic tilt that encourages separation of the vertebral bodies on the side of pain, opening the intervertebral foramen to decompress the irritated nerve root. The precise placement and height of the blocks are determined by the specific findings of the examination, as outlined by DeJarnette 7.
Evidence and research
The scientific investigation into the efficacy and diagnostic reliability of Sacro-Occipital Technique (SOT) consists of foundational theories, case reports, and a limited number of formal research studies. The technique's development by Major Bertrand DeJarnette, a chiropractor and osteopath, began in the 1920s, with the Sacro Occipital Research Society established in 1929 to formalize his concepts 1. A central theory is the Sacro-Occipital pump mechanism, which is proposed to be integral to the Primary Cranial Sacral Respiratory Mechanism. This mechanism is theorized to influence cerebrospinal fluid flow and the nervous system by governing the respiratory motion of the cranium and sacrum 4. These concepts, which form the basis for SOT procedures, were detailed by DeJarnette in his 1984 text, Sacro Occipital Technic 7, and await further empirical validation through modern research methods.
Research examining the clinical effects of SOT pelvic blocking includes a 2006 case series by J.I. Hochman published in the Journal of Manipulative and Physiological Therapeutics 6. This study investigated the application of SOT Category II blocking procedures on five subjects who presented with sacroiliac instability. Following the intervention, all participants exhibited an increase in lumbar spine range of motion in flexion, lateral flexion, and rotation. The study noted, however, that no significant change was observed in the plane of lumbar extension 6. This case series provides preliminary data on the potential biomechanical effects of Category II blocking on lumbar mobility, though its small sample size limits the generalizability of the findings.
The reliability of SOT-specific diagnostic indicators has also been a subject of initial scientific inquiry. One such indicator, the Arm-Fossa Test, is used to identify pelvic fixation. A 2015 pilot study by Cooperstein et al. assessed the consistency between the results of the Arm-Fossa Test and the Gillet test, a widely used orthopedic procedure for evaluating sacroiliac joint motion 5. The authors reported that the preliminary data from their study was consistent with a potential correlation between the two diagnostic tests. However, the findings did not statistically establish a definitive correlation, and the study concluded that larger-scale research is necessary to validate the Arm-Fossa Test as a reliable diagnostic tool 5. The existing evidence base for SOT, while containing supportive case reports and pilot studies, lacks large-scale randomized controlled trials, which are considered the standard for definitively establishing the efficacy of clinical interventions.
Clinical applications
The clinical applications of Sacro-Occipital Technique (SOT) primarily address neuromusculoskeletal conditions, with a strong focus on dysfunction of the pelvis, spine, and cranium. The technique was developed by Major Bertrand DeJarnette, a chiropractor and osteopath, beginning in the 1920s 1. Its most common application is for the assessment and management of low back pain and sacroiliac joint dysfunction. Practitioners use a system of three categories to classify patient presentations and guide treatment. Category II, for instance, specifically relates to sacroiliac joint hypermobility and instability, a common source of low back pain. A 2006 case series by Hochman, published in the Journal of Manipulative and Physiological Therapeutics, investigated the use of SOT Category II blocking procedures on five subjects diagnosed with sacroiliac instability 6. The study reported that the SOT protocol produced a measurable increase in lumbar spine range of motion in all planes except for extension, suggesting a potential positive effect on lumbopelvic biomechanics in this patient group 6. Category III is used for patients presenting with lumbar disc pathology and associated sciatica.
Beyond direct spinal and pelvic complaints, the SOT framework extends to cranial and visceral conditions. This broader application is based on the theoretical link between the sacrum and the occiput, which forms the basis of the technique's name. The gentle, sustained pressure from the pelvic blocks, combined with the patient's own respiratory movements, is theorized to create a "Sacro-Occipital pump" 4. This pumping action is believed to normalize the Primary Cranial Sacral Respiratory Mechanism, a concept describing the rhythmic motion between the cranium and sacrum 4. According to this theory, the mechanism's function is critical for influencing cerebrospinal fluid (CSF) circulation and modulating the autonomic nervous system 4.
Based on this proposed mechanism, SOT practitioners apply the technique to a range of conditions hypothesized to have a craniosacral or visceral-somatic component. These include chronic headaches, temporomandibular joint (TMJ) disorders, and some digestive or respiratory complaints that are thought to be influenced by autonomic nervous system tone. DeJarnette himself outlined these extensive applications in his comprehensive 1984 text, "Sacro Occipital Technic," which details protocols for a wide variety of clinical scenarios beyond simple back pain 7. Because the pelvic blocking procedure is a low-force intervention that relies on gravity and the patient's body weight, it is often utilized for patient populations who may not be candidates for high-velocity thrust manipulation, such as geriatric patients, pregnant women, and individuals with acute pain.
Significance, debate, and limitations
Sacro-Occipital Technique occupies a distinct position within the chiropractic profession, valued by its practitioners for its unique diagnostic system and holistic scope, yet subject to debate regarding its evidence base. Its significance stems from its early and comprehensive development by Major Bertrand DeJarnette, who established the Sacro Occipital Research Society International in 1929 to formalize its study 1. Unlike purely segmental or biomechanical approaches to chiropractic, SOT's theoretical framework extends to the relationship between the cranium, spine, pelvis, and visceral function. Central to this is the concept of a Sacro-Occipital pump mechanism, which is theorized to assist the Primary Cranial Sacral Respiratory Mechanism in regulating the flow of cerebrospinal fluid 4. This proposed influence on CSF dynamics and the nervous system informs the technique's wide clinical application, far beyond the musculoskeletal focus detailed in early chiropractic histories 103.
The primary debate surrounding SOT centers on the need for more extensive, high-quality research to validate its complex theoretical constructs and specific clinical procedures. The existing body of evidence contains supportive but limited findings. For example, a 2006 case series by J.I. Hochman, published in the Journal of Manipulative and Physiological Therapeutics, investigated the use of SOT Category II blocking procedures on five subjects diagnosed with sacroiliac joint instability 6. The study found that the procedure resulted in increased lumbar spine range of motion in all planes except for extension, suggesting a positive biomechanical effect 6. However, the small sample size and case series design limit the generalizability of these results.
Further illustrating the research challenges, a 2015 pilot study by Cooperstein et al. examined the consistency between a foundational SOT diagnostic procedure, the Arm-Fossa Test, and the established orthopedic Gillet test for sacroiliac joint fixation 5. The authors noted that the preliminary data was consistent with a potential relationship but failed to formally establish a statistical correlation, highlighting the difficulty in validating SOT's unique indicator system against external benchmarks 5. Such findings contribute to a perception of SOT as a system with a long history and a dedicated clinical following but one whose foundational tenets remain partially isolated from mainstream evidence-based validation. While DeJarnette's 1984 text provides a detailed manual for its application 7, the mechanisms described within it await more rigorous scientific substantiation. Consequently, while SOT offers a low-force, systems-based approach that many clinicians and patients find effective, its broader acceptance is constrained by the ongoing need for research that can meet contemporary standards of evidence and bridge the gap between its historical theories and modern scientific inquiry.
Sources
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Sacro Occipital Research Society International - https://sorsi.com/about-sorsi/
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Bertrand De Jarnette, Sacro occipital technique 1982 (1982) - https://openlibrary.org/works/OL1591432W
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The secret history of chiropractic by Simon A. Senzon (2005) - https://openlibrary.org/works/OL9914472W
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researchgate.net - https://www.researchgate.net/publication/235773173_Sacro-Occipital_Technique
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semanticscholar.org - https://www.semanticscholar.org/paper/Assessment-of-Consistency-Between-the-Arm-Fossa-a-Pilot-Cooperstein-Blum/9294d1b846e4c70a6c0b3223f6696b01b63da0b7
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Hochman JI, Journal of Manipulative and Physiological Therapeutics (2005) - https://www.jmpt.org/article/S0161-4754(05)00244-6/fulltext
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Textbook of chiropractic technique by F. P. DeGiacomo (1981) - https://openlibrary.org/works/OL6099349W
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Walter I. Wardwell, Chiropractic (1992) - https://openlibrary.org/works/OL4280776W
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Three generations: a history of chiropractic by David D. Palmer (1967) - https://openlibrary.org/works/OL6449150W