shacklock neural mobilization principles and techniques

1. NEURAL MOBILIZATION

2. OBJECTIVES
• Nerve anatomy and physiology
• Clinical biomechanics of nerve
• Pathomechanics(pathophysiological and
pathomechanical)
• Principles of neural mobilization
• Demo
• Evidence on all NTT

3. Introduction
• Concept of continuous tissue tract
1. Both CNS and PNS need to be considered as one since
they form a continuous tissue tract
2. This system is continuous in three ways
• The connective tissue is continuous although different
in format (epineurium , duramater). A single axon is
associated with number of connective tissues.
• Neurones are interconnected both electrically and
chemically.

4. Introduction cont
 The Nervous system
• Includes all the neural tissue in the body
 Neural tissue
• Neurons
-- cells that send and receive signals
• Neuroglia (glial cells)
-- cells that support and protect neurons

5. Central Nervous System
• Nerve roots are considered to be more a part of central
than peripheral nervous system which include meninges
, lack schwann cells & receive nutrition from CSF.
• The connective tissue of the nerve trunks are very diff
from those of the roots even though the same axon is
present in the ventral roots.
• Many authors have drawn attention to the fact that the
connective tissue coverings in nerve roots are much
weaker, or not present at all(Murphy 1977).

6. CNS cont.
• Gamble(1964) conducted an electron microscopy study &
found the connective tissue of the nerve roots were
more like leptomeninges(arachnoid &Piamatter) than
that of peripheral trunk.
• Watanabe (1985) using an electron microscope found
that each rootlet has a pial layer and it resembled a
wispy sheet of gauge.
• There are a no. features at the nerve root level for
transmission

7. CNS cont..
• The fourth, fifth, sixth cervical spinal nerves has a strong
attachment to the gutter of respective transverse
process.
• At segmental level dural & epidural tissues form a
connective tissue sheath which include epidural
sheath(Dommisse & Hause et al ).
Beyond the dorsal root ganglion this sheath forms
the epineurium & perineurium. These attachments are
not immediate as there is no mechanical equivalent to
perineurium in nerve rots.

8. CNS cont…
The epidural tissues and the dura combine to form
epineuriuma and the outer layer of perineurium where
as the endoneurium is the continuation of the
pia(Sunderland 1974, Hanse et al 1985)
• The dural sleeve forms a plugging mechanism which
helps in preventing the nerve root being pulled away
from foramina but also distributes force.
• Nerve roots have their own inbuilt mechanism for
nutrition and protection. CSF does both the activities
(Rydevik et al).

9. The Neuraxis
• The neuraxis (spinal cord ) is the continuation of medulla
oblangata and extends app to L2 vertebral level and it
tapers to form conus medullaris.
• Breig(1978) notes two methods of neuraxial adaptation
to stretch
 Unfolding and untwisting as axons straighten
 Movements in relation to neighbouring vertebral
segments.

10. The Meninges
o Pia & Arachnoid mater :
• These are very delicate membranes far more than
duramater. A mesh or lattice of collagen fibres make up
the pia and arachnoid maters.
• This allows stretch & some compression without kinking
(Breig 1978) and they protect the neural elements and
allowing the movements at the same time.
o CSF, Sub arachnoid &Subdural spaces :
• The subarachnoid space contain CSF .

11. • It acts as a hydraulic cushion surrounding the cord and
nerve roots.
o Dura mater
• Outermost layer meningeal layer & by far the toughest
and the strongest which contains collagen and some
elastin fibres arranged longitudinally (Tinturi).
• This gives the dural theca greater axial strength (Haupt
&Stofft ).

12. Neurodynamics
• Definition : Clinical neurodynamics is essentially the
clinical application of mechanics and physiology of the
nervous system as they relate to each other and are
integrated with musculoskeletal system.
• General layout of the system :
Mechanical interface : It is defined as that tissue or
material adjacent to the nervous system that can move
independently to the system.

13. • Neural structures
• Innervated tissues
The first is that they provide the basis for some causal
mechanisms that therapists should pay particular
attention.
The second reason is for making specific reference to
the innervated tissues is that they provide the therapists
with the opportunity to move nerves.
The third reason is for the treatment basis(Laban et al
1989).

15. Mechanical functions
• Tension :
The first primary mechanical events in the nervous
system is generation of tension.
Since the nervous system is attached to each end of the
neural container the nerves are lengthened by
elongation.
Perineurium : This is the primary guardian against excessive
tension and is effectively cabling in the peripheral
nerve(Sunderland 1991).

16. • Dense packed connective tissue and forming each
fascicle this possess considerable longitudinal and
elasticity.
• It allows peripheral nerve to withstand approx. 18-22 %
strain before failure(Sunderland 1991).
Sliding of nerves : The second event is movement of
nervous system relative to their adjacent tissues.This is
called excursion or sliding(Wilgis &Murphy 1986).
It is of longitudinal and transverse .

17. • Longitudinal sliding :The sliding of nerves down the
tension gradient enables them to lend their tissue
toward the part at which elongation is initiated.
• This way tension is distributed along the nervous system.
• For eg. Median nerve at elbow

18. • Transverse sliding: It occurs in two ways –
The first is to enable the nerve to take the shortest
course between two points when tension is applied.
The second means by side way pressure by
neighbouring structures such as muscle and tendons.
Sliding of peripheral nerve in the nerve bed is
provided by mesoneurium and internal sliding of the
fascicles.

19. • Compression : Neural structures can change their shape
when pressure is exerted on them.
• A clinical example ulnar nerve in elbow flexion .
• The epineurium is the padding of the nerve and it
protects the axons from excessive compression.
• It contains finer and less densely packed connective
which gives them spongy qualities and enables the nerve
to spring back when pressure is removed.

20. How nerves move
Movement of joints :
Convergence –The nerves move in the direction of the joint
because that is where elongation is initiated. The effects
of the two ends produce little or no movement of the
nerves relative to joint roughly at the midpoint.
convergence ocurs in limbs (Smith&Swash
1976) and spine at most mobile segments(C5-6,C4-5)
during sagittal movements(Adams&Logue1982).

22. • Nerve bending:
The bending of the nerural structure around
the interface is a good example of the combining of
fundamental events to produce a more complex action.
Ex: Ulnar nerve at elbow

23. • Movement of innervated tissues:
In addition to longitudinal forces being applied to
the nervous system from the adjacent to the nerve, the
innervated tissues can be used to produce such events.
For instance Dorsiflexion of foot and toes used to apply
tension on sciatic nerve.

24. Movement of interface

26. • Nervous system responses to movement.

27. Physiological evenets
• Intraneural blood flow:
Blood flow of the peripheral nerves is actually
maintained by nerves(nervi vasa nervorum)(Bove&Light
1995).
Nocioceptors and sympathetic fibres are
relevant because in addition to potentially causing pain
they release substance P and calcium gene related
peptide from their terminals into the walls of the blood
vessels(Zochodne & Ho 1991).

28. • Maintanence of blood flow during movement:
During normal movement, nerve blood
flow is preserved through an intricate system of vessels
that distort the nerve.
At rest, vessels are coiled and during
movement they become uncoiled rather than
stretched(Sunderland & Lundborg 1998).

29. Neurodynamic sliders

30. Neurodynamic tensioners

31. Spine
• Mechanical interface
• Neural
• Innervated tissue

32. Flexion and extension
• Mechanical interface- Spinal canal
Flexion of the whole spine causes elongation of the
spinal neural structures because they, and their canal are
located behind the axis of rotation of the spinal segments.
• Neural tissues
Tension and strain are the two responses for flexion.
The amount of tension is not clearly known but strain from
lumbar extension to flexion in lumbar dura can reach
30%, sacral nerve roots 16%(Adams&Logue; Yuan et al 1988).

33. • Sliding and convergence
Sliding of neural structures is complex in spine
and specific sequences of movements their own sliding.
for eg. Neck flexion produces cephalad sliding
of neural structures in lumbar region(Breig 1978).
However SLR produces caudad sliding of the nerve roots
in the lumbasacral foraminae(Goddard & Reid; Breig
1978).

34. Lateral flexion and lateral glide
• Mechanical interface
The key event with lateral flexion in relation to
mechanical interface is that the intervertebral foraminae
close down ipsilateral side and open on the contralateral
side(Fujiwara et al 2001).
• Neural effects
Lateral flexion produces increased tension in the
neural structures on the convex side of the spine and
reduce tension on the concave side(Selvaratnam et al
1988).

35. Increase in tension occurs in two ways :
The first is that lateral flexion itself produces
elongation of the interface and neural tissues on the
convex side.
The second is by causing an increase in
distance between the spine and the periphery by
sideway translation of the vertebrae(Louis 1981).
Uses :
1. Structural differentiation.
2. Sensitization.

36. Others
• Contralateral neurodynamics.
• Bilateral neurodynamic techniques.

37. General Neuropathodynamics
Mechanical interface
dysfunctions
Neural Dysfunctions
Innervated tissue
dysfunctions

38. Mechanical interface dysfunctions
• Reduced closing
Closing dysfunctions • Excessive closing
Opening
dysfunctions
Pathoanatomical
dysfunctions
• Reduced opening
• Excessive opening
• Eg .Spondylolisthesis
• Malignancy
Pathophysiological • Inflammation
dysfunctions

39. Closing dysfunctions
• Reduced closing
Symptoms :
Key behavioural aspect is symptoms increase with closing
movements.
Physical findings:
1. Posture :
In acute and severe dysfunctions a protective deformity is
frequently apparent. This deformity is always in the opening
direction so as to reduce pressure on the adjacent neural structure

40. • Excessive closing
Symptoms :
• Provoked by closing mechanism.
• Hypermobility, instability or habitual closing exist.
Eg. Hyperlordotic lumbar spine.
History :
• Habitual posture or posture imperfection is common.
• Sometimes a history of trauma and features of instability also
instability

41. Opening dysfunctions
• Reduced opening
Symptoms :
• Usually aches and pains in the localized area with or without
referred pain.
• Opening movements provoke pain and are usually restricted.
History :
• Usually history of trauma exists in which patient has been forced
into opening positions.
• The body then compensated during healing process to produce
inflammation and muscular bracing such that opening movements
are reduced to avoid further provocation.
• Eg. Spine

42. • Physical findings:
The reduced opening dysfunction produce a protective
deformity on the ipsilateral side unlike closing type has on
contralateral side.
This deformity is specially designed to reduce tension in the
interfacing and neural tissues.
• Palpation :
Tenderness, muscle tightness and thickening.
Eg. L4-S1 segments may be accompanied by tenderness and
tightness of ipsilateral erector spinae as they limit contralateral
flexion.

43. • Excessive opening
Symptoms :
• Aches and pains and can produce referred pain.
• Pins and needles ,numbness can occur in this dysfuction.
• Symptoms are intermittent and they are produces when provoking
movements are done .
Physical findings
• No deformity occurs in this type.
• Opening movements are increased and that leads to this disorder.
• Ex. Cervical region contralateral flexion and rotation.

44. • Palpation :
Tenderness over specific sites is often present.
Hypermobilty produces mechanical irritation of
the relevant structures.

45. Neural dysfunctions
Neural sliding
dysfunction
Neural
tension
dysfunction
Hypermobility

46. Neurodynamis tests
• What to observe – changes in movement, movement
diagram.
• Planning the examination.
• Levels.

47. • Level 0 – neurodynamic testing contraindicated.
Any contraindication for manual therapy generally exists for
neurodynamic testing.
• Level 1 – limited examination
Indications :
1.When symptoms are easily provoked and takes long time to settle
after movement.
2. In cases of severe pain.
3. Presence of any neurological deficit.
4.When problems shows a progressive worsening after physical
examinantion

48. Level 2- Standard examination
Indications and contraindications:
• The problem is not especially easily provoked and symptoms are
not severe.
• Neurological symptoms are absent.
• When pain is not severe at the time of examination.
• It
is
contraindicated
when
problem
is
unstable, hypersensitive, irritable or when pathology is present

49. • Higher level of examination:
Indications and contraindications:
1. The level 2 testing is normal and didn't reveal sufficient
information.
2. Symptoms are stable and not easily provoked.
3. When there is no pathology that might adversely affect the
nervous system.
4. Contraindications same as level 2.

51. • General points on technique:
•
•
•
•
•
•
•
Explanation to patient
Bilateral comparison
Test the unaffected side first
Maintain each movement precisely
Be gentle and donot hurry
Evoke versus Provoke
Short duration of testing.

52. Standard neurodynamic testing
• Slump test
• Straight leg raise
• Prone knee bend

53. Slump test
• Introduction:
This is used to evaluate the dynamics of neural
structures of the central and peripheral nervous system from the
head, along the spinal cord, sciatic nerve tract and its extensions.
Indications :
Headache, pain anywhere in the spine,pelvis and the lower
limb.
Preparation:
Pt sits with posterior aspect of their against the couch with
their thighs lying parallel. The parallel placement of thighs is for
internal consistency(differences in pelvic size of male and female)

54. Steps in slump

55. • Level 1: Neurodynamic sequencing
Stage 1:
If the patient sits without provocation of
symptoms, they adapt the starting position of the slump. However
if they cannot sit altering the position is necessary.
In this level thoracic and lumbar flexion is avoided.
Instead neck passive flexion and straight leg raise is used.
Stage 2 :
neck flexion is performed by the patient while the
therapist supports patient forehead to prevent rapid descent of
head.
Stage 3 :
Dorsiflexion may be performed passively and is
followed by passive knee extension.

56. • Level 3a(neurodynamically sensitized)
The level 3a position of the slump test incorporates
additional sensitizing manoeuvres of medial rotation and adduction
of hip, dorsiflexion of ankle and contralateral flexion of spine.

58. SLR
• Introduction:
The SLR is used to test the movement and mechanical
sensitivity of the lumbosacral neural structures and their distal
extensions.
• Indications:
It is generally applied in cases of pain and other symptoms in
the posterior and lateral aspect of the lower quarter but its use can
be warranted in examination of the thoracic spine.
• Preparation :
Pt in supine lying with the body aligned symmetrically .In it
purest form the test is performed without a pillow.

59. • Method
• Structural differentiation
proximal symptoms : use dorsiflexion
Distal symptoms: hip flexion produces distal symptoms
so further differentiation is required.
Active cervical flexion : not required

60. • Normal response:
The normal response to the SLR is pulling and
stretching in the posterior thigh that spreads into the
posterior knee and sometimes upper third of calf(Lew&
Slater 1988).

61. • Level 1 :
Technique: Pt is in supine lying with straight knee if
possible .Passive dorsiflexion is performed and the limb is
raised slowly to the first onset of symptoms.
• Level 3a
Technique : the straight leg is raised to the first point of
symptoms, then internal rotation and adduction are
performed and dorsiflexion is added at the end.

62. Treatment giudelines
• Mechanical interface
Not to provoke symptoms.
Initially performed as atrail for 30-60
seconds.
• Neural components
sliders : One ended
Two ended

63. • Tensioners : One ended
two ended

64. Lumbar spine and radiculopathy
• Mechanical interface
Reduced closing dysfunction : level 1
Position -- contralateral side lying with hip and
knee flexed to 90 degree.

65. Static openers

66. Dynamic closures

67. Neural dysfunctions-cephalad