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Flashcards in Neurodynamics Deck (34):

Fun Facts

Spinal cord length is 7-10cm longer in flexion than extension

the median nerve must adapt to be 20% longer w/ wrist & elbow flex/ext


Common Tension Points

C6, T6, L4, Posterior knee & Anterior elbow




axoplasm = nerve cytoplasm

"transport system" w/n the nerve that carrys cell components to and from cell bodies and terminal ends

Axoplasm is thixotropic - meaning it is movement and circulation dependent so if you are immobilized your axoplasm is not moving either


Nerves & Blood

Demands 25% of cardiac output

NS accounts for 7% of body weight

The peripheral nerve can be elongated 8%, after this point the blood circulation is cut off and there can be possible damage to the nerve


Pain Generators (7)

blood flow (ischemia), axoplasmic flow (immobilization/ischemia), double crush, connective tissue, Abnormal impuse generating sites(AIGS), Substance P and surrounding tissue injury

Inflammation and ischemia are main causes of neural symptoms


Blood Flow - ischemic nerve injury

minor compression (30mmHg) can cause ischemia

edematous stage will occur if venous flow restriction is held long enough

Resulting in a swollen and painful nerve


Immobilization - effects on axoplasm & nerve

axoplasm moves up to 100-400mm/day

if there is no motion or ischemia the flow will slow or even stop

3 weeks --> degenerative changes in myelin
6 weeks --> collagen deposition in th eendoneurium
6-16 weeks --> decrease fiber diameter of myelinated fibers


Double Crush

when injury to one area of the nerve can lead to pathology in other sites of the nerve

Double crush = symptoms DISTAL to the site of injury
(hit your funny bone and you feel it in your hand)

Reverse double crush = symptoms PROXIMAL to the site of injury


Connective tissue

connective tissue is highly innervated w/ free nerve endings and Pacinian corpuscles (pressure sensors)

surrounded by unmyelinated fibers containing pain neuropeptides

Connective tissue is 50% of diameter of nerve, so major source of pain generator


Abnormal Impulse Generating Sites (AIGS)

vascular injury to the axon can cause ion channels to get stuck in the axolemma and begin to fire

when the axoplasm stops moving due to ischemia, the ion channels will remain open creating a persistent issue

the pain is DIRECTLY coming from nerve signals, no underlying tissue injury

SYMPTOMS: n/t, temperature or pressure changes

TREATMENT: movement!


Substance P
- normal vs. abnormal pain process

NORMAL - stimulus followed by descending inhibition
- Glial cells quiet, normal amt of substance P released

ABNORMAL - no inhibition from descending pathways
- glial cells activated releasing inflammatory chemicals which increases substance P

--> this response is common in fibromyalgia patients


Surrounding tissue injury

can cause nerve injury due to swelling in the area of the injury

May require immobilization


Two ways to test neural tension:

1. Palpation
2. Neural Tension testing
- placing the nerve on tension w/ different movement techniques

Positive findings = comparable sign, asymmetrical ROM, change of sensation in the distribution of the nerve being tested


Sliders vs. Tensioners

Sliders = flossing the nerve through the surrounding tissue w/o tensing the entire length of the nerve
- acute injury or very irritable symptoms
- i.e. elbow flexion --> extension

Tensioners = tensioning of the entire length of the nerve
- chronic injury or low irritability
- i.e. SLR w/ IR and adduction


Principles of Neural Tension Treatment (3)

- allows for fluid movement
- in PAIN FREE range, stop before any symptoms

- 1 second duration to allow for blood flow

- 25-50 repetitions, 3-5x/day
- start lower and work up tolerance


Straight Leg Raise (SLR)

Perform test passively, watch for posterior pelvic tilt or stop when symptoms arise

Positive test = comparable symptoms, asymmetrical ROM, change in tissue tension when compared to unaffected side

0-30deg --> sciatic nerve
- due to large disc herniation and nerve tension
- educate about CE syndrome

30-70deg --> lumbosacral nerve roots (L4 - S2)
- to check if neural, slack, then DF the ankle

Anything beyond this would be hamstring or soft tissue


Neural testing candidates

nerve root compression
nerve root tension
disc herniation
radiating symptoms
instability --> leading to compression


Added Components to SLR

Dorsiflexion = tibial nerve

Dorsiflexion + inversion = sural nerve

Plantarflexion + infersion = peroneals

Hip adduction = lumbosacral plexus

IR = lumbosacral plexus


Difference between Slump test and SLR

- Slump is more aggressive (perform last)
- can also pick up anything in the thoracic spine (disc herniations/nerve root compression)
- puts more tension on the dura mater


Method of the Slump Test

1. Patient slumps, apply OP to bow the spine
2. Ask patient to take chin to chest, apply OP to CS
3. Extend knee
4. Dorsiflex

Positive test - symptoms must change w/ neck and foot motion
- if only changes w/ foot motion then most likely a lower nerve issue (local) and would not be a positive slump test


Prone Knee Bend (PKB)

indication: upper lumbar radiculopathy, anterior thigh/hip/knee pain

puts tension on femoral nerve and L2-L4 nerve roots

Is it tightness in the quads or tension on femoral nerve
- must compare to the other side
- reproduction of symptoms w/n 80-100 degrees of motion (that would be a really tight quad)



slump test for the femoral nerve (in side-lying)

1. patient lies on side in trunk & neck flexion
2. patient draws lower leg in and pull knee to chest
3. examiner places top foot on their hip and flexes knee (plus hip extension)

must confirm findings w/ head and neck flexion and extension and knee flexion and extension

good test for differentiating nervous system involvement from non-nervous system structures


Slump test in Long-sitting

for people who are extremely flexible or if low disc issue to really wind up the lower NS first
- tension in nerves in LE and lower trunk is taken up first

allows for better assessment of thoracic and cervical movements in sitting

1. patient is long sitting
2. trunk flexion + OP and neck flexion + OP

Confirm findings w/ neck flex/ext

May add foot DF as well


Median Nerve Testing

Shoulder abduction +
Elbow extension +
Shoulder ER & supination +
Wrist & finger extension


Radial nerve testing

Shoulder abduction +
Elbow extension +
Shoulder IR & pronation +
Wrist & finger flexion


Ulnar Nerve testing

Abduction +
Shoulder ER +
Elbow flexion +
Pronation +
Wrist extension


Common entrapment of peroneal nerve

low LS
superior tib/fib
lower limb compartments
ankle extensor retinaculum


Common entrapment of tibial nerve

recurrent HS injury
plantar fasciitis
heel spurs


Common entrapment of Sural nerve

recurrent ankle problems,
Achilles tendinopathy


Common entrapment of Femoral nerve

L2-L3 NR syndrome
pinch/hyperextension @ inguinal ligament
hip flexor strain


Common entrapment of Saphenous nerve

swollen fat pad
---> responsible for almost all arthroscopic medial knee pain


Common entrapment of Median nerve

C5-C6 NR
Carpal tunnel
post-colles fx


Common entrapment of Radial nerve

upper arm, against humerus (post humerus fx)
lateral epicondyle
supinator muscle
DeQuervain's tenosynovitis


Common entrapment of Ulnar nerve

Cubital tunnel
Guyon's canal