Jason Zafereo, PT, OCS, FAAOMPT

With contributions from: Leslie Nelson, PT

Principles of NeurodynamicsObjectives

� Participant will review the relevant

anatomy and function of the peripheral, central, and autonomic nervous systems

� Participant will describe the intraneural and extraneural factors contributing to

nerve injury

Objectives

� Participant will describe the tension

points in the body where pathology is most likely to occur

� Participant will review a system of examination for adverse neural tension

Foundations of Anatomy

� Continuous tissue tract

– Connective tissue interconnected

– Electrically interconnected neurons

– Chemical consistency

� Neurotransmitters

� Cytoplasm

Structure Meets Function

� Accommodation of body movements

– Meninges

– (Endo, peri, epi)-neurium

� Impulse conduction

– Axons

– Myelin

Peripheral Nervous System (PNS)

� Axon

– Run undulatory course in endoneurial tubes

� Myelin

Peripheral Nervous System

� Diagram of Connective tissue coverings

Central Nervous System

� Nerve roots

– Undulations

– Dural and epidural meninges

– Extrathecal attachments

(low cervical, LS)

– Plugging by dorsal root

ganglion

Central Nervous System

� Spinal cord

– Undulations

– Movement in relation to neighboring vertebral segments

– Meninges

� Pia and arachnoid mater

� Dura mater

Autonomic Nervous System

� Sympathetic trunk and ganglia

� Pre-ganglionic neurons

– Head and neck C8-T5

– UE T2-T10

– LE T10-L2

� Post-ganglionic neurons

– Efferent to smooth muscle and glands

Intraneural Causes of ANT

� Decreased blood supply to nervous system

� Disruptions in axonal transport

� Nociceptive stimulation of connective tissue

coverings of nervous system

Vascular considerations

� 2% of body mass consumes 20% of

available Oxygen

� CNS: Critical vascular zone exists from

T4-T9

– Narrow spinal canal

� PNS: Arrest of blood flow at 8%

elongation, complete at 15%

Axonal transport systems

� Two-way movement of materials and

substances in the cytoplasm

� Double crush

Innervation of Connective Tissue

� Meninges– Dura mater highly

innervated ventrally

– Arachnoid/pia mater innervation uncertain

� (Endo, peri, epi)-neurium– Intrinsic innervation

– Free nerve endings

Extraneural Causes of ANT

� Mechanical Interface

– Spinal foramen

– Muscle/fascia

– Joint

– Ligament

– Blood vessel

Intraneural versus Extraneural Symptom & Sign Differentiation

Extraneural Intraneural

(Conducting)

Intraneural

(Connective)

Description of symptoms

Catches, twinges around

vulnerable areas

Burning, tingling, electric in

innervation field

Lines of pain, along trunks,

nondermatomal

Physical signs Comparable signs with

movement of interfacing

structure

Neurological signs and

symptoms; palpation refers

sx elsewhere; increased sx with

tension testing

Palpation elicits local pain;

increased sx with tension testing

Sites of Injury

� Soft tissue, osseus or fibro-osseus tunnels

� Where the nervous system branches

� Where the system is relatively fixed

� Where the nerves pass over unyielding interfaces

� Tension points

Tunnels

� Median nerve in carpal

tunnel

� Spinal nerve in

intervertebral foramen

� Posterior interosseus nerve in arcade of Frohse

Branches

� Union of lateral and medial

plantar nerves to form the common plantar digital

nerve

Fixed System

� Common peroneal nerve at

head of fibula

� Dura mater at L4

� Radial nerve to the head of radius

� Suprascapular nerve in scapular notch

Unyielding Surface

� Cords of plexus over

first rib

� Radial nerve in radial

groove of humerus

� Dural sleeve at pedicles

Unyielding Surfaces (continued)

� Greater occipital nerve

through fascia

� Lateral femoral

cutaneous nerve through fascia

� Nerves in feet through

plantar fascia

“Tension Points”

� Key points in the body where movement

demands (and tension) are increased

– C6

– T6

– L4

– Tibial nerve at posterior knee

– Median nerve at anterior elbow

Neurodynamic Examination

� Tension testing– Longitudinal deformation

– Elasticity intraneural

– Elasticity extraneural

� Palpation– Perpendicular deformation

� Neurological testing

Tension Testing

ULTT1 SLR

Palpation

� Palpate nerves under tension

Final thoughts…

The interconnectedness of the nervous

system must be considered when evaluating and treating patients with

adverse neural tension. These patients

are often misdiagnosed, so check for adverse neural tension when treatment is

not progressing as planned.

Thank You