Clinical Biomechanics of Posture (CBP) is a system of chiropractic spinal analysis and care developed by Donald D. Harrison, M.S., D.C., M.S.E., Ph.D., and Glenn Harrison, B. S., D.C. The approach to improved patient well-being, as designed by these doctors, is a mechanistic one.

To some extent, these mechanistic concepts are justified in that the spine and nervous system have many machine-like qualities. The spine is composed of bones, muscles, blood vessels and neural networks which resemble beams, motors, hydraulics and computers, respectively. Ball and Carlson have stated, "The use of engineering modeling in biological systems is now commonly accepted."

Protocol of Care

The CBP protocol of care begins with the initial patient encounter and a case history, followed by a traditional orthopedic and neurological examination. 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 radio-graphs is performed which will be 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 carefully complex mechanisms.

Mirror Image Adjusting

In chiropractic biophysics, abnormal human posture is analyzed and corrected by 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 adjustment is applied.

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.

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. (3,4) 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.5’6

Conclusion

The CBP 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.