Scientific Basis for Chiropractic
Is there any Scientific Basis for Chiropractic?
Anatomy and Physiology as it relates to chiropractic paradigm (last update 09-19)
I have written this section for my patients who over the past 30 years have wanted to
understand how chiropractic care works. I have been very fortunate to have a diverse
patient base, including teenagers, manual labors to college professors and other
healthcare providers. All people who wanted to understand the science behind the
chiropractic paradigm. To do this, it is necessary to understand that most of the
information that now is understood about anatomy and physiology has been updated
and revised by current research. Much that I am relating has been published in many
different forums from research to clinical observation. I know that some think or believe
that most health care interventions are as well grounded in science as what I am
The information below is from generally available references and links that can be
found in the library or on the web. There are extensive textbooks and articles on these
topics available, but these are usually only found in the bookstores and libraries of
chiropractic colleges. (Not a lot of students, other than chiropractic students study the
different names of all the joints and articulations involved in the spine or have an
interest in the names for each of them.)
So here some of the science of today! (Follow the Blue links or UNDERLINED on
PAGES to the science references)
The two joints on the back surface of vertebrae are called a facet or zygapophseal
(Back View of the spine-typical)
These joints (facet or zygapophseal) are the ones which are involved
in guiding stability of the back and were believed to have a passive role in back activity such as walking and almost everything else.
(Side View of spine-typical)
This is one of the earlier models of how the back worked and it is called "The Box Theory".
The problem with this model is that the energy expenditure of walking was possible, but the energy of running did not make fit this model.
The world's fastest runner would have to look like this person, if the model was accurate.
This is a part of one of the model's that is used currently to describe the back during a static posture position. ( Harrison Model )
When you start looking at an animated movement model, the best current model is the spinal engine model developed by a physicist Serge Gracovetsky PhD . He was not trained to know how the back functioned so, from his paradigm as a physicist, he looked at bipedal gate from an evolutionary prospective. His theory states that bipedal gate cycle are an adaptation of the flexion-extension movements of whale and the left and right lateral movements of a shark.
Not intentionally, Gracovetsky has provided an evolutionary model that follows parsimony in describing the development of bipedal gate. And lays the skeletal (anatomical framework) to describe joint movements that responds to chiropractic care. Not everybody is happy about this and sadly the detractors are not aware of the other important research that gives teeth to this theory.
Just as the ear has specialized receptors that process sound into information that is stored in the brain
And the eyes have specialized receptors called rods and cones-
The joint capsular ligament, with its innervation forms a receptor field. The capsular (facet-zygapophseal) receptor fields also have impact on secondary location distant to the facet - zygapophyseal joint . The chiropractic term for the neurological aspect of this effect was originally subluxation . Then the term subluxation complex was added to better describe the different aspects (vascular, neurological, lymphatic, skeletal, etc.) Later the term, for the neurological aspect, was updated to Dysafferentation .
Upton Sinclair quotes "It is difficult to get a man to understand something, when his salary depends on his not understanding it."
The typical human spine has 48 joints called facet or zygapophseal joints. Here is the start of some of the more traditional medical doctors explanation of the spine.
The medical description of this phenomenon was described in " The Human Spine in Health and Disease " by Georg Schmorl (5th German edition by Herbert Junghanns). The description was more of a staging of the process of subluxation than an anatomy and physiology description.
The initial localized problem was called an Inefficient Motor Segment (Intervertebral Insufficiency) Definition
Group 1 - Changes and complaints in the immediate vicinity of the disturbed motor segment.
Group 2- Symptoms which are conducted through neural and vascular pathways and which also have been termed as symptoms (spondylogenic) of syndromes of spinal cause.
Group 3- Spondylogenic disease which have become independent and have developed originally from the second group.
The neuroanatomy of the facet or zygapophseal joint was first partially described as
the note that there was a nerve that innervated the joint capsule recurrent meningeal
This evolved into the frame work of describing a complete classification of the nerve
ending (receptor types) that innervate the joint capsule of the (facet or zygapophseal)
Today, the neurological parts of these joints take on a totally different importance; not,
just it's a chiropractor invented term "subluxation" to be dismiss. The claims of several
detractor of chiropractic, is that it has no basis in scientific writings. The follow
information may lead the cause of the honest intelligent scientist to re-examine that
The next major step is to understand that the joint capsule is a (primary and
rudimentary) receptor field and what the implications of that realization means. To
begin with a background of receptor field processes is needed to follow the importance.
The idea that we have five senses and the receptor fields are separate and distinct is
one of those learned scientific truths that may more accurately describe a built in
scotoma (blind spot). The first example that seeing is only with the eyes was
complexities of the nervous system connection, to which the eyes did not need to be in a complex organism.
The ability to condition (Pavlov) internal organs all that is required is a receptor field which can be an interconnected to another receptor field. ( Cerebral cortex internal organs ) (This book is available in many university libraries.)
Then the idea that the Psychoneuroimmunology is a real field of study pioneered by Robert Ader PhD makes one begin to consider the possible mechanisms how some of the remarkable occurrences that have been purported to be noted with spinal adjustments.
The typical human spine has 48 joints called facet or zygapophseal joints. The above
information can be simple state as the following: The capsular ligament(s) when
viewed with an electron microscope reveals the existence of receptors. These
receptors classified by Dr B Wyke MD as articular receptors (three different types
receptors are in the capsular ligament of spinal facet joints). These rudimentary
receptor fields display the same properties, as most receptor fields, and can be
conditioned aka Pavlov, convey information to the spinal cord and cerebellum (aka Sc
Am. Rethinking the Lesser Brain). Several different mechanisms can influence the
function of these receptor fields to generate spasm, splinting and/or pain. Sensory
substitution in rehabilitation has since the original research taking on a whole new
dimension with its implication for patient directed care. Then the TM Joints (jaw joints)
seen patients with this problem). If you are a researcher, make sure to read the full
PDF of this article, to understand the impact of the joint receptor fields on the muscles
involved in mandible function. I am certain that joint function follow parsimony in
biology and this is representative of most joint capsule function. This is my current
working model and I am providing this information for clarity.
Nerve signal appear to play a significant role in the development of a fetus and even
Cancer is no more a disease of cells than a traffic jam is a disease of cars. A lifetime of
study of the internal-combustion engine would not help anyone understand our traffic
D. W. Smithers
It is almost amusing that you hear, some professors, at some university, call
chiropractic voodoo science.
This has produced new insights into many fields of study, including physiology. Forces
exerted on a cells structure is propagated through the microstructure architecture and
The implications of connects between different systems of the body is through an
elaborate precise system of feedback. This begins to lay the foundation for
understanding of how many different procedures such as: acupuncture, different
chiropractic techniques and light effects tissue(s).
Here is a recent addition of information on Articular Neurology and Manipulative
Therapy from Donald E. Ingber MD, PhD, at Harvard Medical School
One explanation of how manual therapy works is provided by Donald E. Ingber MD,
PhD, at Harvard Medical School (2008) who argues for the concept of cellular
mechanotransduction, the process by which cells sense mechanical forces and
transduce them into changes in intracellular biochemistry and gene expression. Based
on a prolific, federally funded research program over a number of years, Dr. Ingber has
been studying cells on the nanometer scale. He views the cytoskeleton as an
architectural structure that actively generates tensile forces and distributes them to
other components inside the cell. Ingber (2006) suggests that in the living body the
process of cellular mechanotranduction might be more a phenomena of structural
hierarchies and biological architecture than the action of any single
mechanotransduction molecule. This has significant implications for the field of manual
therapy. Ingber (2006) states that to seek out and study individual biological parts in
isolation without considering contributions of multiscale architecture and invisible
internal forces means we will never be able to fully understand how physical forces
influence biological form and function.
The cellular/tensegrity research of Ingeber (2008), connective tissue research of
Langevin et al. (2001 and 2002), and the fascial research of Schleip (2003) are critical
in our understanding of connective tissue and its applications in the manual therapies.
Wykes mechanoreceptor research (1980) has been instrumental in understanding the
effects of the manual therapies and in particular joint mobilization/manipulation. Schleip
(2003) explains the importance of fascial mechanoreceptors, and with manual
changes can occur in the viscosity of the ground substance and a lowering of
sympathetic tonus. Schleip (2003) has also found smooth muscle cells in fascia that
appear to be involved in active fascial contractility and have only been reported in large
fascial sheets. Pacinian corpuscles are also found in the peritoneum (Stilwell in Schleip
2003 page 15) and can be influenced by manual therapy (Schleip 2003}.
Mechanoreceptors have been found in the visceral ligaments (Schleip, 2003). The belly
(enteric) brain (Gershon in Schleip 2003 p. 17) contains more than 100 million neurons.
Many of these sensory neurons function as mechanoreceptors.
Next I will discuss the other issues:
Failed back surgery syndrome" is a common problem with enormous costs to patients, insurers, and society. The etiology of failed back surgery can be poor patient selection, incorrect diagnosis, suboptimal selection of surgery, poor technique, failure to achieve surgical goals, and/or recurrent pathology.