All neural tissue has to adapt to constantly changing joint angles and alterations in the position of the adjacent tissue. Muscle imbalances, joint dysfunctions, and postural distortions place abnormal tension on the neural tissues. This affects the structural integrity of the neural structures and leads to abnormal neurodynamics.
Review of the Neuroanatomy of the Peripheral Nervous System
The Peripheral Nervous System (PNS) includes:
1. The Spinal Cord
2. Spinal Nerve Roots
3. Spinal Meninges
4. Root Gangflon
5. Spinal Nerve
The peripheral nerve trunk is composed of the nerve fibres, blood vessels, and connective tissues. The connective tissues that surround the nerve fibres include the perinerium, epinerium, endonerium, and mesonerium. These connective tissue structures form a tough, supporting framework for the contained neurovascular triad. The neural connective tissue are self innervated by the nervi nervorum. This innervation, along with an abundant blood supply, makes the connective tissue of the nerve vet reactive and pain sensitive.
The connective tissues that surround the nerve fibres Include:
1. The Perinerium
2. The Epinerium
3. The Endonerium
4. The Mesoneriun
Acute injury (compression), chronic injury (repetitive microtrauma), muscle imbalances, joint dysfunctions, and poor posture compromise the integrity of the neural tissues. Any tissue trauma initiates a neurogenic reflex mechanism, the cumulative injury cycle and creates morphological changes in the microenvironment of the neural tissue. This results in intraneural edema, chemical irritation, tissue hypoxia, and microvascular stasis.
All of these alterations stimulate the nocioceptors and result in pain. Pain causes protective muscle spasms to decrease the provocation to the inflamed neural tissues, which causes altered length-tension relationships, force couple relationships, joint arthrokinematics, and altered movement patterns. This process eventually leads to intraneural fibrosis, which decreases neural tissue elasticity.
Nerve Tension Impairments
The peripheral and central nervous system is a continuous tissue track. Structurally and functionally, there is continuity
Nerve Injury
Etiology: Biomechanical injuries to the peripheral nervous system occur most commonly from friction, compression, and stretch. Secondary injury could occur from blood or edema. The insult could be acute from trauma or chronic from repetitive trauma or entrapment.
Vulnerable Sites: Sites where a peripheral nerve is more vulnerable to compression, friction, or tension include:
1. Tunnels (soft tissue, bony, or fibro-osseous).
2. Branches of the nervous system (especially if the nerve has an abrupt angle).
3. Points where a nerve is relatively fixed.
4. When passing close to rigid structures (across a bony prominence).
5. At special tension points.