Barrett L. Dorko, P.T.
I first came across the idea of neural tension while at
dinner with the late David Lamb, one of the original architects of manual
therapy education in
Deduction and Induction
Like any detective, scientists reason in various ways in an
effort to move closer to the truth. Any therapist allied to science as a
discipline (in my experience, not all are) is probably familiar with the two
classical forms of reasoning; deduction
and induction. Deduction is a form of reasoning that makes specific predictions
from general premises while induction goes
in what might be called the opposite direction-it moves from particular facts to
general statements. Knowing the tolerance of connective tissue to mechanical
stress we can say that it will fail in certain ways-this is deduction. Seeing a
pattern of callous formation on the hand we can safely assume that repetitive
stress is placed upon the limb-this is induction.
Appropriate therapeutic intervention is dependent upon the
use of both induction and deduction and I’m sure you can see this if you think
about what you’re doing to the patient and why. I’m going to leave these two
now and focus on a third less well known form of reasoning.
The following section
was inspired by
In the early 80s a resident physician in
Abductive reasoning follows the following pattern:
Some phenomena P is observed.
P would be explicable if H were true.
Hence there is reason to think that H is true.
In other words, the scientist confronts puzzles that arise
naturally during the course of their work, thinking about them in light of their
intimate knowledge of the system and then they make a creative leap of the imagination to
say, “This would all make sense if H were true.” I find it interesting that this sort of reasoning is
both very familiar and entirely absent from the various discussions about
evidence based practice.
Abduction and Neurogenic Pain-The Problem of “Like Goes With Like”
The patient says, “I know it’s the muscle because I can
feel it.” Those of us familiar with abnormal neurodynamics know full well that
this complaint is due to a nervous irritation and that the muscular nociceptors
aren’t significantly involved. We also know that our efforts to change this
thinking and get the patient to understand and pursue treatment designed to
restore normal neurodynamics may prove rather difficult. This isn’t because our
idea isn’t plausible or too complicated. It’s just new, and because the meme
of muscular pain is fighting for space in the patient’s brain and is already
entrenched there, there’s no guarantee that our idea will win this battle. It may
help to throw all of our authority and clinical skills into the fray, but
success is never assured.
The root of this problem is explained by Gilovich and
Savitsky in a brilliant article titled “Like Goes With Like: The Role of
Representativeness in Erroneous and Pseudoscientific Beliefs” (Skeptical
Inquirer March/April 1996). The authors describe the use of heuristics,
“judgmental shortcuts that generally get us where we need to go-and
quickly-but at the cost of occasionally sending us off course” to make
connections that appear logical but are untrue. (See “The Fatal Heuristic”
elsewhere on this site. Also, read the book "Blink:The Power of Thinking Without
Thinking" by Malcolm Gladwell) They use the supposed similarity between the sensation
produced by stress in the gut and that produced by a peptic ulcer as an example
of a heuristic that led physicians to believe that stomach acid produced ulcers.
They were wrong of course, but the doctor’s personal, visceral experience
hooked that meme powerfully into their consciousness and dislodging it in favor
Similarly, the traditional ideas concerning the presence of
“musculoskeletal” pain and the role of the contractile tissue as weak or
short or lengthened or injured or in spasm or palpably sore is entrenched and
encouraged by many wonderful and effective clinicians. It’s been my experience
that teaching an alternative to this thinking that includes the latest studies
in neurobiology has little effect on their theory or practice. Acceptance of the
concept of abnormal neurodynamics as the primary reason for chronic discomfort
requires that therapists shift the meme of muscular pain from its central role,
and this will be allowed only after a major battle ; a battle the idea of
abnormal neurodynamics may not win.
; a battle the idea of abnormal neurodynamics may not win.
So how did
Breig do it? And, how did those of us who have revised our thinking about chronic
pain relinquish the memes imbedded in our brains concerning the traditional
attitudes about musculoskeletal pain and replace them with the concepts of
neurodynamics and the consequences of its abnormality? I’m proposing that we have engaged in abduction. We have listened
to countless patients describe sensations that cannot be explained using the
paradigm offered us in school and one day said instead, “If abnormal
neurodynamics were present that would account for the patient’s complaint-it
would explain their story in a way that doesn’t violate what we now know to be
true about the nervous system.”
This sort of reasoning is neither common nor easily done.
It requires study, creativity and, most of all, courage.
Do it anyway.