Biomechanical Lesion:
A Better Diagnostic Term for the Profession

This section is compiled by Frank M. Painter, D.C.
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FROM:   Dynamic Chiropractic ~ September 9, 2012 ~ FULL TEXT

John R. Bomar, D.C.

For those who may not be aware, the World Health Organization's latest revision of the International Classification of Diseases (ICD-10) uses a new primary term to describe the major condition treated by chiropractic physicians.

The new term is biomechanical lesion and the code is M99, with decimal designations used for various sections of the body e.g., M99.01, Biomechanical lesion, cervical region. It is thought that the ICD-10 system will be required sometime in 2014.

More than a few chiropractors, myself included, feel this change in nomenclature is much-needed. The present term, non-allopathic lesion (739 series), completely fails to communicate the nature of the problems we address daily in our offices, and the term non-allopathic implies the concept of "non-medical," as if what we treat has little to do with a person's health. Such a maldescriptive phrase does nothing to clear up the confusion and misconceptions associated with our work misconstructions that only contribute to the apprehension and fear many feel when considering our profession.

Such vague and indistinct terminology also discourages appropriate referral from other health care providers. Important also is the current void in understanding that exists between chiropractic providers and the insurance industry. Complicating all this is the insistence by some in our profession that others conform to our definition of the word subluxation, which is in conflict with the accepted medical definition. The natural reaction in others to such uncertainty, obscurity, confusion and doubt is a hesitancy to involve oneself in such dealings, further isolating our profession and hindering growth.


The term biomechanical is defined as "the study of the mechanics of a living body, especially of the forces exerted by muscles and gravity on the skeletal structures." The word biomechanics developed during the early 1970s, and was the application of engineering mechanics to biological and anatomical systems. Mechanical engineering disciplines such as continuing mechanics, mechanism analysis, structural analysis, kinematics and dynamics play prominent roles in the study of human biomechanics. Above all else biomechanics is the study and appreciation of functional order (and disorder) of the human locomotion system.

Interestingly, biological systems are usually considered much more complex than man-built systems. And as we know, the biomechanics of the spine are the most complex of all the body's regions.

In the past several decades, a great amount of research has been done in the field of sports biomechanics, with emphasis on reducing injury, rehabilitation following injury, and enhancing sports performance. The biomechanics of the human being is a core part of the study of kinesiology. Disturbed biomechanics is an integral part of determining permanent impairment following trauma such as motor vehicle crash.

In short, biomechanical is now a widely understood and easily comprehended term with 40 years of usage; there is no ambiguity or uncertainty in its definition.


The term lesion is defined as "any pathological or traumatic discontinuity of tissue or loss of function of a part." Note again the use of the word function. Additionally, lesion is derived from the Latin word laesio, which means "injury." The term is used with an almost unlimited number of conditions and is universally understood to imply some form of gross anatomical abnormality. It is interesting to note that in describing the conditions they treat with manual methods of adjustment and mobilization similar to ours, our philosophical cousins, osteopathic physicians, have long used the term osteopathic lesion.

Biomechanical Lesion

The term spinal biomechanical lesion then would imply a pathological condition involving discontinuity (loss of cohesion) of tissue, and loss of normal vertebral joint function (kinesio-pathology) that often has injury as its cause. It is a very descriptive term, and one that should be well-understood by any and all who have training and study in the field of medical terminology. It's a phrase that is easy to get your head around, no matter your particular discipline.

The Subluxation

Unfortunately, there will be those within the chiropractic profession who will resist, if not vehemently oppose, the use of this new diagnostic term. They will insist that any deviation from using the term subluxation is professional heresy and that any who propose such a change are working against the best interests of the profession. One even hears of individuals who brag that as chiropractors, we "own" the word subluxation.

What these well-intended "defenders of the faith" fail to acknowledge is that, regrettably, subluxation is both ambiguous and misleading, and has led to much confusion and controversy in the larger health care world. In conventional terms the word refers to a "significant structural displacement of bone" that is clearly visible on X-ray. As we know, this is simply not the case for the conditions we commonly treat.

Conclusions and diagnoses drawn from minuscule differences in measurement of anatomical landmarks taken from neutral-static X-ray images (methods many of us were taught in school) have little or no basis in science. Such anatomical measurements are, for the most part, simply not reliable in identifying regions of functional loss and biomechanical lesion formation. One must rely on skilled, experienced and artful palpation to discern regions of biomechanical impairment in the spine or elsewhere, perhaps aided by weight-bearing X-ray imagery. (Lines of mensuration on functional or motion studies to determine ligamentous laxity and permanent biomechanical impairment, and standard orthopedic lines of normal positional relationships and angles, are exceptions.)

I am sympathetic to those who want to prosper the word because of its supposed connection to the concept of somatovisceral reflex. I too believe that what we do affects the nervous and organ systems of the body in a positive way, and that many disorders and pathological processes have their root cause in spinal "impingements" from biomechanical cause. But without using the bewildering and perplexing term subluxation complex, one could, for example, easily describe a "biomechanical lesion formation at the upper cervical region which is possibly etiologic for pathological somatovisceral reflex and sympathetic vasomotor dysfunction, resulting in migraine-type headache syndrome."

Again, it is easy to understand those who feel a strong affinity for the term subluxation; however, the sad truth is the word has outlived its usefulness in today's world of mass communication and instantaneous Google searching. The profession can no longer afford to embrace a primary diagnostic term that only adds to the confusion and distrust of our motives and methods. Quibbling over semantics in disregard of harsh, punishing reality makes absolutely no sense.

There is already enough misunderstanding, distrust and misconception about what we do. Why add to the confusion? This is especially true as regards interprofessional communications and relations.

Please forgive me for observing, but in the larger world of health care delivery, beyond the somewhat narrow and at times myopic confines of chiropractic circles, the term subluxation has become a millstone, if not an albatross around our necks. Clearly, it is time to put the term to rest.

Dr. John Bomar, a 1978 graduate of Palmer College of Chiropractic, practices in Arkadelphia, Ark. He is a past board member of the Arkansas Chiropractic Association and a founding board member of the Arkansas Chiropractic Educational Society. Contact Dr. Bomar with questions and/or comments regarding this article via e-mail:


Since 9-19-2012

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