An Explanation of “Dural Drag”
Dural drag is a phrase and concept coined by Australian Acupuncturist, Bowen Therapist and Naturopath Graham Pennington, is refers to the irritation placed on the Dura Mater and how that disturbs the global system of the body, at the deepest possible level.
The Dura Mater is the outermost layer of the meninges which cover the brain and spinal cord. This structure is primarily made up of a thick, tough, and inelastic fibrous connective tissue, characterized by its dense, white appearance.
Cranial Dura Mater
Within the skull's protective enclosure, the dura mater is differentiated into an external endosteal layer and an internal meningeal layer, interconnected by obliquely arranged fibrous connections.
The endosteal layer is distinctly rough and closely adheres to the inner contours of the cranial bones, effectively serving as their internal periosteum and hosting the vasculature for bone nourishment.
In contrast, the meningeal layer is notably smoother, coated with an endothelial layer resembling that of serous membranes. Its folding is responsible for the formation of significant dural partitions like the falx cerebri, tentorium cerebelli, falx cerebelli, and diaphragma sellae.
This layer securely anchors around the foramen magnum's perimeter as it transitions from the cranial cavity.
Dural Membrane Tension
Research by Upledger and colleagues highlights that directional tension applied to the cranial dural membrane encourages the fibrous components to align with the tension's orientation, potentially indicating the predominant stress directions experienced by the dura mater. This phenomenon suggests that distortions in the cranial structure directly influence tensions within the cranial dura mater.
Spinal Dura Mater
As the dura mater extends beyond the skull, the endosteal layer discontinues at the foramen magnum, extending anteriorly down to the third cervical vertebra, integrating with the periosteum of the cervical vertebrae. Below this juncture, the spinal dura mater predominantly comprises the longitudinally oriented meningeal layer.
Spinal Dural Attachments
Discoveries by Hack et al. in 1995 established a dural attachment at the atlas, with a detailed observation of a myodural bridge linking the posterior atlanto-occipital membrane to the dura mater. This linkage appears to limit dural folding during neck extension, thus preserving cerebrospinal fluid dynamics.
Similarly, findings by Mitchell and Humphrey in 1998 identified a connective tissue bridge from the ligamentum nuchae to the upper cervical vertebrae, which seems to mitigate dura mater movement during cervical spine extension. This feature is particularly enhanced in the posterior aspect of C1 to C3, bolstering resistance to folding.
The spinal dura mater envelops the spinal cord, separated from the vertebral canal's walls by an epidural space filled with a venous network and areolar tissue. It is firmly attached to the cervical vertebrae and exhibits variable connections to the posterior longitudinal ligament, with these attachments becoming denser in the lumbar spine region.
The Link between the Cranium and Spine
Tensions within the cranial dura mater can transmit to the spinal and pelvic structures, potentially leading to vertebral misalignments and systemic imbalances. This underscores the intricate relationship between cranial and spinal health. This dural- mediated spinal misalignment pattern can not be effectively addressed with methods aimed solely at spinal correction. Something must be done in order to release the tension within the dura mater before any lasting correction of the spine can be effected. (This is the goal of ALB- correction of the dural tension)
The Cranial Nerves
Each cranial nerve is encased in a dural sheath, suggesting that tension within the cranial dura mater could affect nerve function. This is exemplified in the optic nerve, where dural tension impacts its function, suggesting a correlation between cranial structural misalignments and neural performance. In light of the positive changes in vision often times noted by recipients of ALB, the question must be asked as to whether the dural tension developed by cranial bone misalignment (sphenoid is the "key stone" to cranial bone alignment) and its transference to the optic nerve sheath and sclera can be partially to blame.
The Pituitary Gland
Nestled within the sphenoid bone's sella turcica, the pituitary gland is covered by the dura mater, specifically through the diaphragma sellae. This arrangement prompts considerations on how cranial dural tension might influence the gland's communication with the hypothalamus, affecting endocrine functions. As we see positive results many times achieved with ALB and endocrine disorders, the question must be asked as to whether some negative effect upon hypothalamic - pituitary communication is exerted as the cranial vault dural tension is transmitted to the diaphragma sella and the to the infundibulum piercing it.
The Epineurium
The epineurium, as the outer connective tissue covering of spinal and peripheral nerves, extends from the dura mater, indicating that dural tension could propagate to peripheral nerves, potentially explaining certain neuropathies. Furthermore, its continuity with the fascial tissue suggests that cranial dysfunction can have widespread effects across the body. Thus, tension developed within the cranial and spinal dura may be transmitted to these nerves as well perhaps resulting in many of the “unexplained” peripheral neuropathies encountered in clinic.
Fascia
Viewed as a continuous connective tissue sheet, the fascia integrates closely with the dura mater and the epineurium, indicating that cranial disturbances and resulting tension can have extensive implications on body-wide systems and tissues.
Upledger discusses the direct relationship of 4 -5 layers of fascia to the cranium itself.
Suffice to say that cranial dysfunction (once again sphenoid) with resulting tension referred into the fascia can have very far reaching effects on virtually all systems and tissues of the body.
Other Considerations
The presence of fascial damage or dural adhesions have been observed in dissection, particularly following injuries or inflammation, can exacerbate tension within the dura mater, complicating the resolution of Dural Drag.
Conclusion
Exploration reveals the extensive implications of Dural Drag on bodily health, affecting the nervous, structural, muscular, endocrine, and organ systems. Abnormal restriction to the Dura and the associated tension can significantly stress these systems.