Dr. Joseph Dolak

Chiropractic Biophysics
Chiropractic Biophysics Technique
By Donald D. Harrison, D.C., Ph.D.

Chiropractic biophysics is a system of chiropractic spinal analysis
and care developed by Donald D. Harrison, M.S., DC, M.S.E., Ph.
D., and Glenn Harrison, B.S., DC The approach to improved
patient well-being, as designed by these doctors, is a mechanistic

To some extent, these mechanistic concepts are justified in that
the spine and nervous system have many machinelike qualities.
The spine is composed of bones, muscles, blood vessels and
neural networks which resemble beams, motors, hydraulics and
computers, respectively. Ball and Carlson1 have stated, "The use
of engineering modeling in biological systems is now commonly
accepted as a logical means of approaching highly complex

The Rationale for CBP
CBP applies the sciences of mathematics, physics and biophysics
to the practice and theory of chiropractic. While the simple
analogies of a bone "stuck" or "out of place" may serve doctors
well when communicating with patients regarding spinal
adjustments or some form of therapy, they hardly reflect the
degree of sophistication which is necessary in communicating with
the rest of the scientific community. The plight of our profession
can be simply summed up in the following statement from the
report of the New Zealand Commission of Inquiry Into Chiropractic:
"The exact nature of such defects (subluxations) has not yet been
demonstrated; nor has the mechanism by which its apparent
effects are produced." The 1975 NINDS workshop on the status of
spinal manipulative therapy made the observation that "there was
no quantitative or qualitative reproducible description of

Chiropractic biophysics is addressing these shortcomings by
combining the discipline of science, the foundational principles of
chiropractic and the application of technical skills to attempt to
elucidate the truth about what we do, how we do it and how we
can do it better. CBP attempts to understand and apply the
universal laws which govern the behavior of matter and energy
and their interactions in biological systems. The result of over 12
years of development is an ever-expanding and evolving base of
work and literature relating to the science of what chiropractic is
and does. Currently, the CBP technique represents a full spine
and pelvis corrective/rehabilitative procedure having a firm
foundation in the sciences of mechanics and physics and providing
both a qualitative and quantitative model of chiropractic practice.

The overall goal of the CBP technique is to restore normal three-
dimensional human posture. Methods include "mirror image"
posture adjustments, rehabilitative exercises, cervical extension
traction and manual procedures. In CBP, the overall posture or
global positioning of the spinal column is targeted for correction, as
opposed to individual spinal segments.

In CBP, the optimum static position of the upright human spine is
established with the Harrison spinal model. A subluxation is
considered to be any postural deviation from this mathematical
norm. The model represents the most complete chiropractic effort
to date to establish what constitutes "normal."

Although not perfect, the Harrison model is a starting point and a
reasonable clinical objective for corrective care. It is expected that
as our knowledge expands, so too will the model expand and

Protocol of Care
The CBP protocol of care begins with the initial patient encounter
and a case history. The patient is then analyzed for abnormal
posture in every possible degree of freedom of the skull, thoracic
cage and pelvis. Next, an exacting series of radiographs is
performed which are then analyzed using geometry to obtain
information for formulating care plans and later to serve as an
objective standard against which to evaluate the efficacy of care.

Following careful consideration of pertinent clinical findings,
especially the correlation of the patient’s three-dimensional
posture with its two-dimensional X-ray image, a patient’s case is
either accepted or referred to an appropriate specialist. Patients
who are accepted for care are generally assigned to one of two
regimens (i.e., acute or corrective care). Factors, which might
influence the appropriate type of care, could be numerous, such as
the nature of their specific complaint, the magnitude of their
postural distortions and the degree of pathophysiology associated
with subluxation degeneration.

Patients who are selected for acute care would receive a program
of care perhaps not unlike that of many non-CBP offices. They
would undergo "diversified"-type adjustments (both long- and short-
lever) to restore segmental mobility, cryotherapy to reduce
localized inflammation, passive and active stretching and massage
as indicated to reduce spasm and myofascial involvement. Acute
care programs may also apply to corrective care patients who
enter the office symptomatic.

The CBP corrective care regimen includes the use of drop table
and upper cervical instrument-assisted adjustive procedures, as
well as a variety of corrective extension traction procedures and
corrective postural exercises. It is not the methods themselves,
which are unique to CBP, but rather the rationale behind their use
and the way in which these tools are employed to accomplish
stated clinical objectives.

The following is a summary of basic methods currently in

Mirror Image Adjusting
In chiropractic biophysics, abnormal human posture is analyzed
and corrected be means of what is termed "mirror-image"
adjustments. Basically this is done by first analyzing the standing
posture in three dimensions and then stressing the patient’s
abnormal posture into its exact opposite, or "mirror," image. Once
the patient has been pre-stressed into the mirror image, a light
adjustive force is applied.

Adjustive forces are generally applied to the atlas transverse
process with either a toggle—type adjustment or by means of a
cervical adjusting instrument. Adjustive forces may also be
introduced to the lower back area by the use of a drop table
adjustment with force applied to the sacroiliac or femur head
areas. The purpose of mirror image adjustment is to introduce
mechanical stimulation to proprioceptors and encourage the brain
to reconsider the faulty postural patterns which have become
habituated overtime. It is precisely these habituated postural
patterns which are a major source of chronic spinal dysfunction
and which result in spinal resistance to correction which all
practitioners have experienced. Mirror image adjustments may be
performed with the patient in either the prone, supine, side posture
or standing positions. Correction to normal posture is then verified
by pre- and post-adjustment postural examinations.

Rehabilitative Exercise
Since adaptation of muscular structures is a process that takes
place over an extended period of time, repetition of positive forces
into the affected tissues is necessary to effectively achieve and
maintain postural correction. These simple techniques alone can
often be quite effective, as demonstrated in a 1986 study by Klein
and Sobel of neck pain patients, in which 59 percent received
significant long-term relief from performing postural exercises for
their conditions.

Harrison’s mirror image exercises are set up individually, based on
the patient’s particular abnormal posture configuration, unlike
many generic, "one-size-fits-all" exercise programs. Mirror image
exercise procedures effectively reeducate the body by targeting
those muscle groups and their associated global movements,
which effect a more permanent correction of the patient’s
subluxated posture.

Extension Traction
One of the most common postures, which presents in the
chiropractic office is that of cervical hypolordosis/kyphosis with the
patient’s head in an anterior weight-bearing position. In chronic
cases, ligaments will have creeped shorter and adapted to the
abnormal postures. Due to their specific mechanical properties,
ligamentous tissues do not often respond well to the rapid loading
forces which constitute the chiropractic adjustment. Anyone
familiar with the sigmoid-shaped load-deformation curves obtained
from testing spinal ligaments realizes that rapid loading forces
affect only the elastic range of the ligaments. Loads must be
applied over 20 to 30 minutes to affect the viscous and plastic
regions of the load-deformation curves.

Consequently, the primary purpose of cervical extension traction is
to provide a long duration or slow adjusting force to those soft
tissues that have contracted over time and therefore tend to
perpetuate the patient’s subluxated state.

A variety of traction methods are currently being employed by CBP
practitioners. Performed in the office, these methods may require
times that range from 10 to 20 minutes, according to the doctor’s
discretion and patient tolerance. Many patients also receive a
home traction device so that they may actively participate in their
recovery program.

By use of these methods, CBP field practitioners are experiencing
great success in restoring cervical curves. As evidence of the
success of this approach, a recent controlled clinical trial
demonstrated an average increase of the cervical lordosis of 13.5
degrees versus no statistically significant change in the control

The chiropractic biophysics technique is unique for several
reasons. It provides a specific therapeutic goal (the Harrison model
of ideal upright posture). It correlates the patient’s three-
dimensional posture with precise radiographic analysis to help
eliminate much of the false data, which are inherent in analysis
based on X-rays alone. It effectively addresses the overall posture
of the patient by means of mirror image adjustive procedures, and
it seeks to rectify long-term soft tissue changes by means of
extension tractioning and rehabilitative exercise programs which
are tailored individually for each patient. Through the application of
knowledge borrowed from the fields of physics and mathematics
and university biophysics, we are bringing clinical results into line
with our philosophical tenets.

About the author
Donald D. Harrison, D.C., is the developer of the CBP technique.
He holds BS and MS degrees in mathematics, masters in
mechanical engineering, and also holds a PhD in math in addition
to his Doctor of Chiropractic degree. He is the publisher of the
American Journal of Clinical Chiropractic, which is published
company whose products are geared toward the CBP practice. For
more information on the CBP technique, call (800) 346-5146.


1.Ball, L.D., and Carlson, L.E., Experimental Mechanics of the Spine, 6th Annual
Biomechanics Conference on the Spine, Boulder, Cob.t Univ. of Colorado, 1975.

2.Harrison, D.D., "Abnormal Postural Permutations Calculated as Rotations and
Translations From an Ideal Normal Upright Static Spine," chapter 6, In:Chiropractic
Family Practice, J. Sweere, Ed., Gaitherburg, Md.: Aspen Publishers, 1992.

3. Cochran, C., A Primer of Orthopedics Biomechanics, Churchill Livingstone, 1982.

4. White, A.A., and Panjabi, M.M., Clinical Biomechanics of the Spine, Philadelphia:
1.8.Lippincott Co., 1978.

5. Chasal, J., Tanguy, A., Bourges, M., Caurel, C., Escande, G., Cuilbot, M., and
Vameuville, C., "Biomechanical Properties of Spinal Ligaments and a Histological
Study of the Supraspinal Ligament in Traction," I. Biomechanics 3:167-176,1985.

6. Chow, D.H.K., Luk, K.D.K., Leong, J.C.Y., and Woo, C.W., "Torsional Stability of
the Lumbosacral Junction: Significance of the Iliol Ligament,"
Spine 14:611 -615, 1989.