Neurodynamics (Guest Lecture) Flashcards
Describe the purpose of pain
Pain acts as a “smoke alarm”
It allows the brain to conclude that there is actual or potential damage and that action is required
Give an example that show there is not a direct relationship between pain and dysfunction
Stubbing your toe
Term: Study and relationship of the nervous system mechanics and physiology
Neurodynamics
Descibe how the neurosystem adapts to movement
It just move and stretch all while performing complex eletrochemical processes. Lack of adaptation would result in injury
Give 2 examples of the adaptability of the nervous system
SC lengthens 7-10 cm or 3-5 inches with flexion
The median nerve increases it’s length by 20% from wrist/elbow flexion to extension
5 Points of Greater than Normal Nerve Tension
- C6
- T6** (due to increased lig attachment at SC)
- L4
- Posterior Knee
- Anterior Elbow
Term: Point where there is no movement of the nervous system in relation to the tissue/dura interface
Tension point
CNS Protective Layers
Dura mater
Arachnoid mater
Pia mater
PNS Protective Layers (out to in)
Mesoneurium
Epineurium
Perineurium
Endoneurium
Describe how the connective tissues supporting the nervous system can cause sx
The connective tissues are innervated, inflammation and/or ischemia in these tissues stimulates their free nerve endings resulting in sx
Structure: nerve cytoplasm that acts as a transport system being nourishment to cells
Axoplasm
Structure: movement and circulation dependent, 3-5x thicker than water
Axoplasm
Describe the nervous systems need for blood
They are blood suckers! While they make up 7% of our BM they use 25% of our Q
Describe the effect of elongation on BF to the nervous system
At 8% elongation BF can become compromised which can lead to nervous tissue damage
7 Nerve Pain Generators
- Blood Flow
- Axoplasmic Flow
- Double Crush
- Connective Tissue
- Abnormal Impulse Generating Sites (AIGS)
- Substance P
- Surrounding Tissue Injury
Descibe the amount of compression need to stop BF and the affect on nerves
30 mmHg of pressure can occlude BF resulting in a swollen nerve
Term: Movement dependent
Thixotropic
Decribe the flow of Axoplasm
Axoplasm moves 100-400 mm a day. Immobilization or ischemia can slow or even stop flow. This flow is movement dependent (thisotropic)
Term: Experience symptoms distal to the nerve injury
Double crush
ex. hitting your funny bone
Term: Experiencing symptoms proximal to the nerve injury
Reverse double crush
ex. CTS producing neck/shld pain
Describe how double crush/reverse double crush is possible
Because the nervous system is a closed system injury in one area of a nerve can lead to pathology in other nerve sites
Describe how connective tissue can generate nerve pain
CT makes up 50% of the diameter of a nerve and it is highly innervated (free nerve endings, pacinian corpuscles) as well as surrounded by unmyelinated fibers containing pain neuropeptitides
Describe AIGS
Axons transmit messages, the ion channels used to transmit an AP typically are recycled every 2 days. However, if there is vascular injury these channels can get stuck in the axolemma and fire at random in both directions. These miss fires can manifest as N/T, burning, pressure, etc. Without axoplasm flow this can persist.
Describe how Substance P generates nerve pain
When a nerve processes information abnormally, substance P and excitatory amino acids are released in excess. This stimulates glial cells to release inflammatory agents (NO, cytokines, prostaglandins) which inturn stimulate further release of substance P
Describe the what is happening in regards to nerve recovery at
- 3 wks
- 6 wks
- 6-16 wks
- Degenerative changes in myelin
- Collagen deposition in the endoneurium
- Decrease in fiber diameter or myelinated fibers
2 Ways to feel nerves
- Palpation
- Neural tension testing
3 Good spots to palpation nerves
- Tunnels (ex. carpal tunnel and median n.)
- Branches (ex. radial n. at elbow)
- Hard surfaces (ex. radial n. on radius)
Nerve: Medial to biceps femoris at the head of the fibula
Peroneal n.
Nerve: Lower L-spine, piriformis, superior tibiofibular joint, lower limb compartments, ankle extensor retinaculum
Peroneal n.
Nerve: Posterior to knee and medial to ankle
Tibial n.
Nerve: Plantar fasciitis, heel spurs, recurrent HS injury, piriformis
Tibial n.
Nerve: Lateral to Achilles tendon and distal to fibula
Sural n.
Nerve: Recurrent ankle problems and Achilles tendonitis
Sural n.
Nerve: near the inguinal ligament
Femoral n.
Nerve: Hip flexor strain, pinch/hyperext at inguinal ligament, L2-3 nerve root syndrome
Femoral n.
Nerve: Infrapatellar branches on the head of the tibia and main nerve between gacilis and sartorius at the knee joint
Saphenous n.
Nerve: Most arthroscopic medial knee pain and MCL injuries
Saphenous n.
Nerve: Upper arm, medial to biceps tendon, indirectly at carpal tunnel
Median n.
Nerve: CTS, s/p Colles fx, C5-6 nerve root entrapement
Median n.
Nerve: Pisiform area at wrist
Ulnar n.
Nerve: Guyon’s canal
Ulnar n.
Nerve: Mid humberus and radial sensory nerve onthe lateral aspect of the forearm
Radial n.
Nerve: DeQuervain’s, tenosynovitis, s/p humeral fx, C5-6 nerve root entrapment
Radial n.
Term: When assessing nerve looking to see if tension is reproducing pain/sx. that pt. came to be treated for
Comparable sign
Only REALLY concerning precaution to neural tension testing
Unstable condition - ligament damage, vertebral instability, etc.
Other precautions include: elderly, circulatory disturbance, pregnancy, causes dizziness, pathology to nervous system
4-8 Contraindications to Neural Tension Testing
- Tethered cord syndrome
- SCI
- Cauda equina
- Recent neurological changes
- Malignancy
- Instability in vertebral column
- Recent worsening neurological sx
- Unstable disc lesion
SLR that biases peroneal n.
Add PF and inversion
SLR that biases sural n.
Add DF and inversion
SLR that biases tibial n.
Add DF and eversion
4 ways to increase the overall load of SLR
- IR the hip
- ADD the hip
- Contralateral T/L SB
- Cervical flexion
Describe what the slump test assesses
It is a more aggressive test to assess the posterior leg particularly in pt. who have minimally irritable sx.
Positive Finding from Neural Tension Testing
- Comparable sign
- Asymmetrical ROM
- Change in sensaiton in nerve distribution
Documenting Neural Tension Testing
- Area/sequence of response
- Restriction of movement
- Sx characteristics
