Neurodynamics

Neurodynamics, Neural flossing, Nerve glides...what do these terms mean exactly? The concept of placing a mechanical stress on the nervous system is abstract for many students. While many people learn the common "tensioning tests" in a school lab or at a con-ed course, the knowledge of when to perform these tests AND how to interpret the tests is lost by many individuals. 
    
Clinicians often use neural tensioning tests to determine if a patient has adverse neural tension. If a part of the nervous system becomes inflamed, entrapped, or damaged, the patient will present with signs and symptoms of neural origin. Examples of diagnoses seen with adverse neural tension include carpal tunnel syndrome, cervical radiculopathy, and cubital tunnel syndrome.  By performing tensioning tests, the clinician can determine if the origin (or a component) of pain (or other symptoms) is neural or non-neural. Pain is not your only "positive" finding in the test. Pulling and stretching are just as significant. Basically, if you develop pain/pulling/stretching in an area when tensioning the nerve and it is modified by cervical movement, you need to consider nerve components. A study published in JOSPT in 2012 by Nee et al gives "probable" criteria in regards to diagnosing peripheral neuropathic pain: 1. symptoms fit a nerve related pattern 2. history of symptoms correlates with a nerve related problem. 3. a clinical neuro examination or imaging rule-in or confirm a neurological injury. 

If you suspect adverse neural tension to be contributing to your patient's symptoms, perform a neurodynamic test to help confirm your hypothesis. For example, if you suspect a patient has carpal tunnel syndrome, perform the Median Nerve ULTT first and foremost because that is the nerve most directly involved. When performing the tests, be cautious of false positive results. Many asymptomatic individuals will have adverse neural tension so you must ask yourself if the symptom response is relevant. A general 3-part rule I follow is A. does the + test reproduce the symptoms the patient came to see you for, B. is there a side to side difference, and c. Does the neural response change by moving a distant component. If these 3 components are true, adverse neural tension is likely contributing to your patient's pain. Now this is a controversial topic. Some people follow this 3-step rule. Others look for any findings of neural tension at all (not just pain and not just at the location of chief complaint) as a possible component to the pathology. Why? Because it is not normal.

There are neural tension for both the upper and lower extremities. Many people have heard of the SLUMP, Straight Leg Raise Tests, and ULTTs. You can check out how to perform the ULTT tests below:
1) Median Nerve ULTT
2) Radial Nerve ULTT
3) Ulnar Nerve ULTT

Why is it that we have neural tension and what do we do about the positive findings? Remember, neural tension is not normal, just like hypertonicity is not normal. Trauma (micro or macro) often is culprit. That trauma can be local to the nerve or as a result of abnormal spinal motion. For example, if you have excessive lumbar mobility on one side compared to another, eventually this stress can damage the nerves, leading to pain down the chain. Sound ridiculous? We have seen where a patient had greater lumbar extension R compared to L and had positive SLUMP testing with calf pain. Following a manipulation to the hypomobile side of the lumbar spine, the pain was significantly reduced. Nerve flossing is important for improving the mobility of neural tissue, but we must not forget to correct the original factor that led to the neural tension. In an upcoming post, we will review various methods of how to treat neural tensioning in general along with some other information.

The tests above with help you determine if adverse neural tension is present. The videos below by Chris Johnson will guide your intervention selection.
Commonly used Neurodynamic Interventions by Chris Johnson


As stated early, there are many false positive with neural tensioning tests. It is important that you be consistent and precise with your tension tests to get accurate results. Also, be sure to clarify your patient's responses and watch for compensations in the test positions. A slight variation can completely lose the pathological nerve tension.

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References:
Nee RJ, et al. (2012). The Validity of Upper-Limb Neurodynamic Testing for detecting Peripheral Neuropathic 
     Pain. JOSPT. 2012 May; 42(5): 413-424. Web. 13 October 2013.