Unit 1. Mobilization of the Peripheral Nervous System PDF

MOBILIZATION OF THE PERIPHERAL NERVOUS SYSTEM UNIT 1. ANATOMY, PHYSIOLOGY AND MECHANICS Manual Therapy I Arturo Pérez Gosálvez CEU-Universidad San Pablo ANATOMY, PHYSIOLOGY AND MECHANICS OF THE NERVOUS SYSTEM • INTRODUCTION • GENERAL STRUCTURE OF THE NS. • PROTECTION SYSTEMS OF THE NS. • PHYSIOLO...

MOBILIZATION OF THE PERIPHERAL NERVOUS SYSTEM UNIT 1. ANATOMY, PHYSIOLOGY AND MECHANICS Manual Therapy I Arturo Pérez Gosálvez CEU-Universidad San Pablo ANATOMY, PHYSIOLOGY AND MECHANICS OF THE NERVOUS SYSTEM • INTRODUCTION • GENERAL STRUCTURE OF THE NS. • PROTECTION SYSTEMS OF THE NS. • PHYSIOLOGY • MECHANICAL FUNCTIONS OF THE NS • NERVOUS SYSTEM AS A WHOLE/SET 2 INTRODUCTION 3 INTRODUCTION • ¿Which are the main functions of the Nervous System? • ¿How the Nervous System is divided? • ¿Does/Has the Nervous System movement capability ? 4 INTRODUCTION • The NS is a continuous tissue: – Mechanical Continuity (dura- mater) – Electrical Continuity. – Chemical Continuity. • Any movement of a extremity has consequences in the NS. • Any movement of the PNS has consequences in the CNS. GENERAL STRUCTURE OF THE NS 6 GENERAL STRUCTURE OF THE NS GENERAL STRUCTURE OF THE NS • 1. CONTACT SURFACE / MECHANICAL INTERFACE: – “Tissue or material adjacent to the nervous system that can be moved independently of the system” (Butler 1991). – The mechanical interface acts as a container for the NS. (Shacklock 1995). – The NS must accommodate the tissues around it (interface). – The bio-pathological condition of these tissues can influence the NS by mechanical or inflammatory action. GENERAL STRUCTURE OF THE NS 2. NEURAL STRUCTURES: 2.1 Structures associated with nerve conduction. • Features that allow some mobility. – Neuroaxis (brain and spinal cord) – Nerve roots, dorsal root ganglion, peripheral nerve (axons). 2.2 Conjunctive structures associated. • Protection structures (meninges, endoneurium,...) • Features that allow some mobility. GENERAL STRUCTURE OF THE NS • 3. INNERVATED TISSUES: – Influence causal mechanisms (are the basis of some of them). – The NS interacts with the innervated tissues (afferent and efferent) – Allow mobilization and treatment (through them) of the nerve tissue. 10 PROTECTION SYSTEMS OF THE NS 11 PROTECTION SYSTEMS OF THE NS • 1. MENINGES: – ¿ What structures involve? – ¿What is their function? – Dura- mater. – Arachnoid. – Pia- Mater. PROTECTION SYSTEMS OF THE NS • 1.1 DURA- MATER: – More external. – Stringy/ fibrous, thick and rough. – Collagen and elastin. – It has little longitudinal deformation with capacity for crossadaptation. – Envelop loosely (not tightly) the NS. Parts: - Cranial Dura- Mater. - Spinal Dura- Mater. PROTECTION SYSTEMS OF THE NS • 1.1 DURA- MATER: – Anchores/ Attachment: • Central portions of the skull bones. • Foramen Magnum. • Lateral masses and posterior arch of the atlas and axis. • Sacrum (S2). • Dural ligaments and dorsomedial septums /partitions. PROTECTION SYSTEMS OF THE NS • 1.2 ARACHNOID MATER: – It is interposed between the two other meninges => Intermediate layer. – It is a translucent collagen membrane that envelop loosely the brain and spinal cord. – It is separated from the Dura- Mater by the subdural space. PROTECTION SYSTEMS OF THE NS • 1.3 PIA MATER: – It is the innermost membrane. – It is closely linked to nerve tissue, following its contours. – Microscopically thin and highly vascularized. – Between the pia -mater and arachnoid stands the subarachnoid space, through which circulates cerebrospinal fluid. 16 PROTECTION SYSTEMS OF THE NS • 2. WRAPS/ ENVELOPES OF THE PERIPHERAL NERVE: – Some fibers are coated with myelin and someone not. – Connective tissue sheaths, with longitudinal and oblique arrangement respect the axon. – Have more rigidity/stiffness near joints. – 20% of tissue is elastin (fibers). – May increase, between 15% to 20%, its resting length. PROTECTION SYSTEMS OF THE NS • 2. WRAPS/ ENVELOPES OF THE PERIPHERAL NERVE : – ¡ Both the connective tissue such as neural tissue are likely to respond to mechanical problems! 18 PROTECTION SYSTEMS OF THE NS • 2.1 ENDONEURIUM: – Envelopes the axon. – Formed by collagen matrix. – Maintains endoneurial space and the Cerebrospinal fluid pressure. – No lymphatic vessels, which causes…. that any edema interferes in the function. PROTECTION SYSTEMS OF THE NS • 2.2 PERINEURIUM: – Envelopes several axons and protects the endoneurial tubes. – It is the most resistant structure to the tension/ stress: ¡¡¡until 750 mmHg to be broken!!!!! PROTECTION SYSTEMS OF THE NS • 2.3 EPINEURIUM: - Envelopes the nerve. – Collagen and longitudinal elastic fibers (and may exist fat/grease among the nerve fascicles). – Internal epineurium: It facilitates the movement between the fascicles. Important in joint areas!!! – It allows the gliding, with respect to the mechanical interface. 21 PROTECTION SYSTEMS OF THE NS • 3. WRAPS/ ENVELOPES OF THE NERVE ROOTS: – They are similar to pia mater and arachnoid. – Have structures which allow transmit tension and movement: • Exist anchors of the roots to neighbour structures. • They have possibility to deploy themselves. WRAPS/ ENVELOPES OF THE NERVE ROOTS 23 PHYSIOLOGY 24 PHYSIOLOGY • 1. AXONAL TRANSPORT: – Anterograde: • Fast (400 mm/day): vesicles and neurotransmitters. • Slow (1-6 mm/day): material of the cytoskeleton. – Retrograde: • 200 mm/day. • Recycled vesicles and extracellular material which promotes the neurite growth. ¡¡¡¡Compression may affect these transports!!!! PHYSIOLOGY • 2. BLOOD CIRCULATION: – The NS consumes the 20% of the oxygen. – Irrigation of the CNS: the Circle of Willis. – Irrigation of the spinal cord: vertebral and radicular arteries. PHYSIOLOGY • 2. BLOOD CIRCULATION – Irrigation of the nerve roots: radicular (proximal and distal) artery. – Irrigation of the peripheral nerve: Intrinsic vascular system very extensive, due to can not afford to lack of blood supply. PHYSIOLOGY • 2. BLOOD CIRCULATION: – Decreased blood flow begins with a stretch of 8%, stopping when the stretch is 15%. – Also affects time: 6% stretch for one hour reduces the conduction by 70%. – Compression effects: the threshold is between 30-50 mmHg. – Compression and tension have acumulative effects. PHYSIOLOGY • 3. INERVATION: – Peripheral nerve is inervated by the “nervi nervorum”. – Effects of the sympathetic fibers about the peripheral nerve circulation : vasoconstriction. – Effects of the nociceptors about the peripheral nerve circulation: vasodilation. MECHANICAL FUNCTIONS OF THE NS 30 MECHANICAL FUNCTIONS OF THE NS • Any body movement is going to be transmitted to NS, not only locally. • The body mechanics of the NS must allow pain-free movements without altering the primary function of the SN (transmission of electrochemical impulses) • NS has mechanisms to prevent injuries. MECHANICAL FUNCTIONS OF THE NS • Mechanical interface moves and can produce changes in the NS: - Physiologic mechanical interface. - Pathological mechanical interface • The normality in the movement of the SN depends of its neuro-biomechanical capacity: - Withstand tension. - Slip(slide) into your container. - Be able to compress MECHANICAL FUNCTIONS OF THE NS • 1. TENSION: – Nerves are attached to the ends of the container. – The lengthening of the container "lengthens" the nerve. – The tension increases “intraneural pressure”. – Perineurium is a key protective structure: dense connective tissue. – They can withstand between 18-22% of tension: sciatic nerve (up to 50 kg.) MECHANICAL FUNCTIONS OF THE NS • 2. SLIDING: – “Movement between the neural tissue and mechanical interface”. – Longitudinal Sliding: • Nerves move according to the tension gradient (towards the points of maximum tension and towards the area where the lengthening begins). • Without sliding, neural ischemia would occur. • Add other movements increases tension. MECHANICAL FUNCTIONS OF THE NS – Transverse Sliding: • Find the shortest path when apply tension. * Helps dissipate tension / pressure on nerves • It responds to lateral pressure of adjacent structures. – Permitted by the epineurium. MECHANICAL FUNCTIONS OF THE NS • 3. COMPRESSION: – Possibility of deformation. – Epineurium is which protects from excessive compression. – It has sufficient elasticity to return to the initial position when the pressure is removed. NERVOUS SYSTEM AS A WHOLE/SET 37 NERVOUS SYSTEM AS A WHOLE/SET • NS as a complex system: – Local movements can cause distance changes. • During movement, the tension in the NS is initially located in the local area. • The transmission of forces facilitates that can produce side/ secondary effects in another area. • The spread of the tension and movement is nonuniform. • If pressure is higher in an area, the greater the distance and the mechanisms of adaptation to other areas. NERVOUS SYSTEM AS A WHOLE/SET • Response to movement: – At the beginning, a movement of the NS is produced locally. Then it spreads to distal. – In the medium-haul (path), a very fast neural slip/ glide occurs. – In the end- haul (path), appears a tension in the NS, due to the ability of gliding has decreased. NERVOUS SYSTEM AS A WHOLE/SET – The first part that moves is the one that will be subjected to more stress. – Load receiving in the NS is determined by joint position. Lengthens on the convex side of the joints and shortens on the concave side 40 NERVOUS SYSTEM AS A WHOLE/SET • Structural differentation: – NS continuity allows manual differentiation of the structures involved in the problem. – It is performed by moving the neural structures without moving the musculoskeletal structures in the same area. – It can be done in all neurodynamic tests. BIBLIOGRAPHY • Butler DS. Mobilisation of the Nervous System. Editorial Paidotribo. • Shacklock M. Clinical Neurodynamics: A New System of Musculoskeletal Treatment. Editorial Elsevier. • López Cubas,C. Neurodinámica en la Práctica Clínica. Editorial Zerapi.