Neurodynamics Flashcards
Definition of neurodynamics
Clinical application of mechanics and physiology of the NS as they relate to each other and are integrated with musculoskeletal function
Neurodynamic Tests
Examine contribution of spinal nerve roots and peripheral nerves to extremity pain
- Sequential lengthening of distance the dura travels
- Controlled mechanical stresses to the dura and other neurologic tissues
_____ _____ placed on the dura of the spinal nerve roots and the peripheral nerve roots until ____
Tensile stresses
Until the patient’s symptoms are reproduced
Purpose of neurodynamics
to test for neurologic component to the symptoms
Pathological mechanosensitivity of the nervous system (are the nerves hypersensitive to movement)
Mechanical
What is the nerve doing
Tension - lengthen distance it travels
Sliding - is it gliding as it should
Compression - is something pushing on it
Physiological
Intra-neural blood flow
Inflammation
Mechano-sensitivity (nerve responding to movements)
Causes of neurodynamic pathology
- Mechanical
- Vascular
- Axoplasmic
Mechanical cause
Inc in length neural structures travel
- nerve excursion during extremity movements (tension sites/adherent) - nerve isn’t gliding well
- Pathologic (tumor, disc, osteophyte)
- Musc or articular dysfunction (capsular connection to dura)
- Fibrosis (chronic nerve root adhesion)
Vascular cause
Swelling, ischemia
Hypoxia, increased intraneural pressure
Physiology is not working properly
Axoplasmic cause
Changes with blood flow
- Dec nerve function at cellular level
- Structural alterations (demyelination)
- Abnormal impulses at DRG
Neurodynamic Dysfunction
Nerve trunks exhibit mechanial allodynia
Hypersensitivity of the nervous system
Muscle role
Muscles have a sifignificant role in protection of neural tissues when they are inflamed or hypersensitive to movement –> it will inc muscle tone so as to prevent the nerve from having to lengthen
More of the physiologic than mechanical
Subjective complaitns
- Extremity weakness/heaviness
- Numbness or tingling
- Swelling (may not be visibly swollen though)
- Pain - burning, aching, vague
- “lines” or “clumps” or pain
- Aggravated by positions that inc distance nerve travels
Neurodynamic Examination tests
Slump test
Straight leg raise
Normal test (without any neurodynamic issue)
tingling
stretch
maybe an ache
Positive neurodynamic test
Reproduces their comparable sign
Test response altered by distant movement (dorsiflex ankle and increases back pain = abnormal)
Diff in ROM, resistance, and sx involved vs. non-involved limb
Adverse response to nerve palpation
Diagnositc Accuracy - Straight leg raise
Positive if the patient reports reproduction of LBP of LE pain at 40 degrees or less
High sensitivity (if neg = probably not a neuro problem)
SNNOUT
Diagnositc Accuracy - Crossed SLR
Performed on asymptomatic side and produces symptoms in the involved LE Higher specificity (if positive is a good indicator of a neurodynamic problem)
Clinical Utility
Prone lumbar mechanical traction in patients with signs of nerve root compression
Subjects who have peripheralization with repeated lumbar extension, positive Crossed SLR
If either of those is present, they will do well with traction
Practical handling skille
Joint ROM needs to be examines prior to neurodynamic exam Think in terms of distances - SLR - Knee flexion/extension - Ankle DF/PF/Inv/Ev - Hip rotation - Cervical flexion Gentleness of technique is important too
Neurodynamic Intervention - Passive oscillatory movements
Passive oscillatory movements
- Begin proximally with movement at the spine and moving tissues around the nerve
- Movement of anatomic structures around the neural tissue
- Movement of surrounding tissues and nerve together
- Progressive extremity positioning (adding movements that inc distance it travels)
Neurodynamic Intervention - nerve tensioning
Movement of one or several joints to elongate the nerve bed and the nerve - inc nerve tension and intraneural pressure, reduces intraneural blood flow
Abnormal impulse generation –> trigger ectopic discharges, may exacerbate sx
Neurodynamic Intervention - SLump Stretching
Patients with LBP and LE pain who’s distal sx do not centralize with repeated ext or flex have a positive slump test in absense of radicular sx
Describe a slump stretch
Patient in long sitting with feet against a wall to maintain ankle dorsiflexion
Overpressure into cervical flexion
Neurodynamic intervention - neural sliding
Elongate nerve at one joint balanced by reduction in length of nerve bed at an adjacent joint
- Nerve slides relative to surrounding structures
- Longitudinal excursion of the nerve
Dynamic variation in inta-neural pressure
- This facilitates evacuation of intra-neural edema (helps circulation and provide nutrients)
Reduces sx
Contraindications/Precautions
- Irritable conditions
- Pathology of structures involved (bone spur - like rope starting to fray)
- Circulatory changes
- Malignancy
- Neurological signs
- Cord signs
- Cauda equina lesions
Symptom vs. sign
Symptom = subjective Sign = objective (measurable)
