Myth Busting With Neurodynamics
Updated: May 15, 2020
Imagine how our patients feel. “Facts” they’ve believed all of their lives might not be true. They juggle many opposing views from the internet, to their medical doctor, physical therapist and even family.
Alternatively imagine you’re a new grad coming out of PT school. Good chance you’d also be confused. Social media influencers challenge the status quo on the daily.
Who do you believe? Conscientious professionals want to do what’s best. Patients want best care as well.
What is best anyway?
We imagine it as a set point everyone recognizes. However, what is best exists on a continuum and differs depending on a wide variety of factors.
This is why I was interested in Clinical Neurodynamics, an assessment and treatment approach, under-appreciated in the field of rehab. Misconceptions regarding neurodynamics may reflect a lack of knowledge but several mirror the friction we witness in heated Instagram, Twitter and Facebook debates.
The “myths” identified in this post were chosen because they need challenging, not because they are 100% wrong. In several cases I debated presenting information from the opposite side of the pendulum because the answer doesn’t lie on either side but somewhere in between.
Let’s start off with a bigee.
"Evidence Based Practice Is Best Practice"
But is it?
The implication that evidence based practice (EBP) is the best approach insinuates there isn’t a better way.
Blending best available scientific evidence with clinical expertise and patient’s values is a noble goal. It’s not the intent of evidence-based medicine that's the problem. Misconceptions about EBP and inadequacies in how it is applied have unfortunately served as an excuse to bow out. What we are left with is often a watered down version of EBP.
Here are a few examples of how EBP falls short:
To investigate efficacy, EBP stresses studies that maximize internal validity. This limits the ability for evidence to be applied in real life situations including clinical practice.
Randomized control trials and systematic reviews are considered the penultimate of EBP. They are prioritized in decision-making and development of clinical guidelines while other evidence like case studies are ignored.
Then there's the issue of how well it is implemented clinically. Do we have the knowledge, tools and time to critically appraise the research? Do clinicians resort to cherry picking? Ubetcha.
“Best medical evidence” in EBP should be an integration of many models of inquiry; science based reasoning and clinical experience. EBP and N=1 approaches shouldn’t exist as separate entities. Case studies are critical for precision medicine and a finer understanding of individuals.
Neurodynamics provides a model for EBP: a principle based system applying science-based reasoning to our individual patients with a pathway for treatment.
The field of neurodynamics is guided by a growing body of evidence that investigates mechanisms, normal/abnormal responses, efficacy and effectiveness. This systematic approach focuses on integration of systems and inherently stresses an individualized approach. It’s exactly in our collective body of n=1 studies where we will find progression in the manner of all types of research.
EBP can always be better and it should.
"You Can Find The Root Cause"
But Can You Really?
We can’t say with certainty there is one root cause responsible for someone’s symptoms; even with diagnostic testing, clusters of special tests, and knowing about our patient’s psychological and social issues.
But saying pain is multifactorial shouldn’t be a cop out for us to try and identify these potential factors and help people the best we can.
Neurodynamics is a model that looks at the mechanics of the nervous system with respect to other tissues. It doesn't propose to be the reason for all movement hypersensitivity and uses inclusion and exclusion criteria to guide the practitioner with their decision making.
You don’t stop with a positive neurodynamic test. You seek a greater understanding of what is going on and you do so by understanding mechanisms and integration of disparate systems.
“An abnormal neurodynamic response does not determine its cause.”
Neurodynamic testing can’t identify the point in the continuum of the nervous system that drives one’s symptom sensitivity. We can however perform tests of structural differentiation that attempt to exclude certain factors.
This approach directs us towards an answer that is “less wrong”. Neurodynamics is one part of your thorough evaluation.
“Any user of a map or model must realize that we do not understand a model, map, or reduction unless we understand and respect its limitations. If we don’t understand what the map does and doesn’t tell us, it can be useless or even dangerous.”
And once you found a suspected contributor to symptoms, can you confirm that with your treatment?
"Outcomes Reflect Quality Of Our Clinical Decisions"
But do they?
Outcomes can’t give us a complete picture of what we should take credit for. Clinical decision-making inherently involves choices made with incomplete information. Much like poker, we love to think we control the cards.
In the book Thinking In Bets, Annie Duke refers to equating a good decision to a good outcome as ‘resulting.’ This human tendency is also expressed as the self-serving bias, taking credit for good outcomes and blaming external factors for negative ones.
Instead of adjusting our beliefs to fit new information we tend to alter our interpretation of new information to fit our beliefs. When we do this with our patients’ outcomes we miss opportunities to learn.
A n=1 treatment approach is more than appreciating complexity and the “whole person.” With this approach each patient is a trial in which you are continuously testing that individual and obtaining data on him or her.
When considering results we rarely go through the thought experiment:
If a particular intervention doesn’t work what are all the possible reasons why?
Reflection such as this enhances our ability to estimate probabilities and make better decisions. (eg, probability to cause a flare-up vs. not).
There is much beyond our control but what is in it? Consistency for one. It is key in neurodynamic testing. If you change positioning or sequencing you’ve changed the test. Consistency requires skill. Practicing handling techniques and slowing movements helps refine your senses to attune to your patient’s response.
"Mobilizing Techniques Work By Elongating Tissue"
Are you certain?
There are many ways to gain range. Nerve "stretching" like we've classically thought of stretching is rarely indicated in rehab. It can produce unwanted effects on both nerve and blood vessel function.
Neural tissue does have the capacity to elongate but we need to be careful when discussing both mechanisms of proposed and post-hoc effects of the interventions we use.
Mechanistic reasoning is an integral part of critical thinking because providing vague answers potentially hinders our quest to better understand and find meaning in our care.
Nonetheless, theoretical mechanisms should be scrutinized like other aspects of reasoning. This is how we evolved from conceptualizing the working mechanism of neurodynamics being one of stretching nerves to a mobility technique that aims to decrease hypersensitivity.
In terms of movement, nerves themselves slide, bend, and resist tension and compression.
We can move nerves via three methods:
moving a joint
moving the innervated tissue
moving the interfacing soft tissue.
Mind you, a neurodynamic treatment doesn’t always involve movement. For certain patients with nerve root pain a starting point of positioning with little or no movement is often best. (static openers)
Additional mechanisms considered in clinical neurodynamics include alterations in hemodynamics and other fluid dynamics. We can also explore the potential role of histodynamics, thermodynamics and centrally mediated changes involving the neuro-immune system.
"Nervous System is King"
Can't play the game without the rest of the pieces
When we say the nervous system is king we minimize the role of other systems to the detriment of our decision-making.
Folks still revere neuroplasticity (#cuzbrain) although bioplasticity is a more accurate term. Several biological processes are involved in adaptation to stress.
Many assume neurodynamics is a neurocentric model. However, it is more than the name suggests. A key component of clinical neurodynamics is the interdependence of the musculoskeletal system and nervous system. The noi group describes neurodynamics as affecting the neuro-immune system.
Asking better clinical questions involves looking at problems from multiple angles. In neurodynamics we can change our starting point by inverting the question:
How does the musculoskeletal system influence the nervous system?
How does the nervous system influence the musculoskeletal system?
Thinking techniques like inversion help us remain value-neutral as we test and apply different models. In neurodynamics it helps us integrate mechanics with physiology and the environment.
A neuro-orthopedic exam of most humans will likely lead to a laundry list of findings. You need to decide how and where you intervene. A system that helps us assess and manipulate leverage points can direct.
In Donella Meadows’ categorization of leverage point she ranks “goals of the (complex) system” as one of the most effective places to intervene.
If we consider that the aim of the nervous system is survival and protection we can’t forget that task is often dependent on movement. (watch this) So there you have it: the nervous system and the musculoskeletal system – that is Neurodynamics.
Many of my objections to these stances are nuanced and inherently that is my overriding argument - clinical care is nuanced.
Status quo should be questioned and challenged. This is more effectively done with exploration and dialogue focused on deeper learning than social media sound bites.
Different perspectives are a reality of life. Considering multiple perspectives encourages a more complete picture as we seek to identify what is less wrong and more useful. This requires we level up our professional communication and separate identities from beliefs.
While I have taken both Mobilization of the Nervous System (and the updated Neuro-Immune) course from the NOI group I am biased toward the approach taught in Upper and Lower Quarter Clinical Neurodynamics. Therefore when I cite specifics of “Neurodynamics” I am referring to the course and information I have learned from Michael Shacklock.
If you haven’t yet I suggest looking into this course as I think it will provide you with more than clinical skills, but critical thinking ones that are truly needed to progress.
If you want to learn more about Clinical Neurodynamics, check out their website for future course listings and additional information.
Michael Shacklock’s book Clinical Neurodynamics
David Butler’s book The Sensitive Nervous System.
Also, I have found these books that explore reasoning and mental models helpful:
Thinking in Bets: Making Smarter Decisions When You Don't Have All The Facts
Seeking Wisdom – From Darwin to Munger
The Great Mental Models Volume 1: General Thinking Concepts
The Great Mental Models Volume 2: Physics, Chemistry and Biology
And lastly, if you ever have any yearning questions on Statistics you should check out my brother-in-law's You Tube Channel: StatQuest. Join his > 250K subscribers in getting your statistics questions answered!