L4 - BASIC OF NEURODYNAMIC Flashcards
Roles of peripheral nerves
- Nerves = roots conducting / transmitting information
- Some conduct upstairs, other conduct downstair and other conducts both
- Detect pain, vibration information…
- Refers to central nervous system (brain or spinal cord)
- Nerves play role in doing movement
- Secondary influence over human movement: nerves can restrict human movement, decrease
ROM. Nerves have ability to adapt to human movement. Nerves need to stretch, glide… to have “normal” ROM (limitation of ROM = one of major symptoms) - Nerves can create pain: radiating pain (pain going from point A to point B)
=> Peripheral nerves more than just carriers of info also ability to move in full ROM
Advantages and disadvantages of nerve mechanical interface
Protect nerves
BUT can affect nerve properties
Name 3 main disabilities of nerve properties & describe them
Ulnar neuropathy: ulnar nerve very superficial, compressed by other structures or by external forces
Carpal tunnel syndrome: inflammatory system that creates too much pressure on median nerve
Piriformis syndrome: sciatic nerve compresses due to overstretch or other problem in piriformis muscle
Description of nerves biomechanics
Nerves are not static structures. Nerves moving in direction of movement. Nerves viscoelastic tissues,
presenting:
- Longitudinal & transverse excursion (gliding)
- Strain (elongation of nerve): correlation between forces applied and possible deformations
- Stiffness / rigidity
- Convergence: fibers of nerve move toward same point
- Divergence: fibers of nerve move to different directions, move away to common point
- Stress relaxation / creep: max stretch create pain or discomfort, but if you hold position, few
seconds / minutes, discomfort go down → by elongate = creation of stress but holding position = relax. By maintaining position: increase length of muscle → increase ROM due to chronic
adaptation
- Nerve gliding & convergence
Changes in nerve properties
Physiological effects of tensile forces acting on peripheral nerve:
- Nerve conduction velocity (speed of conduction decrease over the time in case pf tensile or
compressive forces)
- Intraneural blood flow (amount of blood in nerve change depending on external forces on nerve)
Has also been found:
- After immobilization periods, affecting myelin sheet & fiber diameter.
- In people with Carpal Tunnel syndrome, affecting longitudinal excursion & stiffness.
If surgery, because patient has motor changes, not only sensory impairment. Tested with reflexes.
- In people with lumbar radiculopathy, affecting cross-sectional area.
Which types of force can applied on nerve
Chronic forces like compressive and tensile
Possible physiological changes on nerve applied by forces
- Altered conduction velocity
- Altered blood flow
- Edema (not edema like after type 3 ankle sprain, nerve edema = micro level, unmeasurable)
- Limited nerve gliding
Simple definition of mechanosensitivity
= pain during motion
How test mechanosensitivity and why
With neurodynamic tests: ULNT 1, 2A, 2B 3 / Slump, SLR
Used to stress peripheral nerve & identify mechanosensitivity
How work Neurodynamic techniques
Neurodynamic techniques applied gradual stress that increase at each step of test => importance of order of steps and doing properly. Goal is to reproduce symptoms of patient.
Name the 2 different neurodynamic techniques and describe them
Sliders
Sliders = technique that applied tension, by creating tension at one end of nerve but counterbalanced by
movement of another end
Nerve elongation at one end, while releasing tension at another end.
Tensioners
Tensioners = technique that applied tension, fixing one end of nerve and pull other end in opposite direction to increase stress
Nerve elongation at both ends.
=> Tensioners should appear as better technique to test nerve but is nerve compresses, more effective to glide it with sliders.
Name 2 other maneuvers
Sensitizing and differentiation maneuvers
Definition of sensitizing maneuvers
= additional movements increasing stress in peripheral nerve, increasing sensation. To put more tension in specific direction / specific group of nerves. Extra-maneuver to increase
the load of the test.
Definition of differentiation maneuvers
= movements added distant to location of symptoms affecting neural structures in limb without affecting non-neural tissue local to area symptoms. Movement performs far
away from tested region, which change symptoms of patient (increase or decrease pain). Movement performs to better read test, help answer the question of: is it a nerve pathology or not
Give an example of sensitizing maneuvers for Neurodynamic tests of LL
SLR: ankle DF, ankle eversion/inversion, hip ADD ABD…
