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Dynamic Chiropractic – November 20, 2005, Vol. 23, Issue 24

Normal, Ideal, and Optimal Spines

By Robert Cooperstein, MA, DC

On several occasions, I have heard Dr. Pettibon state that to define something in the spine as abnormal, one first has to define what "normal" is. I have always found that logic most compelling, although I do not necessarily find Pettibon's ideal spine or Harrison's version of it very compelling.

The latter altered his model a few years ago so as to wind up in about the same place as researchers whose work he had previously rejected,1,2 although he continues to fine-tune his calculations.

As a result of my training in economic science, I tend to judge phenomena not so much as normal or ideal, but rather, as optimal or not, relative to a desirable goal. In economics, for example, the price of a good or service is optimal when it enables demand to equal supply. A lower price would result in shortages, thus a black market and waiting lines; while a higher price would result in a glut, and costly inventory accumulation. Likewise, I evaluate the spine according to whether it has assumed an optimal structure, one best suited for that individual's function.

These are not just semantics. The concept of subluxation, in most of its definitions, pretty much excludes the concept of optimality, leading to inappropriate diagnoses and goals of care. In fact, sometimes a patient is better off "subluxated" than normal, in the sense of segmentally aligned (as a Gonstead or Diversified doctor might see it), or having an ideal posture, as a structuralist (like Pettibon or Harrison3) might see it. I am going to describe two cases I have seen that illustrate this point quite clearly, and then draw some conclusions.

Case 1: A Friendly Subluxation in a Lawyer

I have a middle-aged patient, a lawyer, who knows many chiropractors, neurologists, and orthopedists in the community in which I practice, mostly because he does personal-injury cases with them. One day, looking in the mirror, he noticed his own very obvious head tilt, which he decided should be corrected. (I guess he didn't like silent killers.) Upon pointing this out to a few chiropractors with whom he was working, he was treated by them for a variety of diagnoses: atlas subluxation, cervical lateral curvature, occiput subluxation.

I guess you know where this story is going: Eventually, it was my turn to examine, diagnose, and treat this lawyer. I found an "uncompensated cervicodorsal angle," meaning an upper-thoracic lateral tilt that was not compensated by an opposite tilt in the upper cervical area. I proceeded to use a pre-stressing method4 I had learned from Pettibon to straighten the spine, which involved performing an anterior thoracic maneuver on the upper thoracic spine, with the spine set up in lateral flexion opposite to the incoming inclination (i.e., pre-stressed toward correction). Harrison calls this mirror-image adjusting,5 but I prefer Troyanovich's term, "inverse postural adjusting."6

It didn't work. No matter what I did, the thoracic and head tilt persisted. Eventually, the patient found himself at a cocktail party conversing with an ophthalmologist, to whom he recounted his unsuccessful experiences correcting head tilt with three different chiropractors. The doctor just laughed. He informed the lawyer that his head tilt was an entirely appropriate compensation for a palsy of one or more of the extraocular muscles. Without the lateral inclination of the head and neck, his eyes would not be carried horizontally on the frontal visual axis; totally unacceptable. The body will do whatever it takes to keep the eyes level, including "subluxating" the thoracic spine and enduring head tilt. Curl's article7 is relevant, as well as the study by Dietrich, et al.8

Might this eventuate in asymmetric spinal weight-bearing and disc pressures, premature arthritic breakdown, or maybe even nerve interference? Sure - but it beats walking into parking meters and driving into trees. I think periodic chiropractic care, in such a situation, can keep the laterally inclined spine flexible and mute the symptoms of spinal degenerative joint disease. I have no opinion as to how often this might reduce palsy in an extraocular muscle.

The thoracic "subluxation" was the solution to the patient's problem, not itself the problem. Might I worsen the lawyer's overall well-being by correcting his subluxation? Not to worry. Whatever I do, so long as his ocular muscles function asymmetrically, he will carry his head asymmetrically.

Case 2: A Young Female Whose SI Joint Refused to Subluxate

Earlier this year, I saw a 17-year-old female who had suffered low back pain for more than 10 years. Although I could palpate paraspinal muscle hypertonus in her low back, that was not my most interesting examination finding. Her PSISs were even in the sitting position, suggesting little or no pelvic torsion.9,10 However, the right PSIS was low in the standing position, suggesting a right anatomic short leg. An inferior standing PSIS also can result from pelvic torsion, but in this case, the seated findings argued against that. I was able to verify that, at least to my satisfaction, with a compressive leg check, a prone procedure optimized to detect anatomic leg-length inequality.

We now know from a number of studies that the innominate bone typically rotates anteriorly (AS ilium) on the side of an anatomic short leg, and posteriorly (PI ilium) on the side of an anatomic long leg. Several references for that fact can be found in my article on pelvic torsion.13 Getting back to the patient at hand, I concluded that even though she had a right anatomic short leg, she had failed to develop an anterior rotation of the right innominate bone, as demonstrated by the sitting PSIS symmetry. In other words, what we had here was a failure to subluxate.

The solution, although I suspect not all chiropractors would find it equally palatable, involved thrusting so as to create a right AS ilium. This required, of course, deploying the same side-posture manipulative procedure that would correct a right PI, even though this particular patient did not seem to have one. Upon seated re-examination, the right PSIS (formerly symmetric with the left PSIS) now was inferior, and the standing PSISs were more even. The chronic low back pain was gone, on the spot. It was still gone during a follow-up visit a few days later, after which I dismissed the patient. If I could have found more time to practice this year, I would have sent the patient a postcard advising her it was time for a chiropractic checkup.

Could I have made this patient worse by creating a "subluxation" where there had been none? I don't think so. I created more sacroiliac mobility, using the correct vector, enabling her body to accommodate to the anatomic short leg, and that was a good thing. I think the immediate abolition of chronic low back pain more than offset any long-term liability created by pelvic torsion. If she becomes symptomatic in the future and does not once again respond to sacroiliac manipulation, I will fit her short-term with a heel lift, and see how that goes.


I will admit to the fact that I have been struggling with the subluxation concept, whether seen as a segmental or structural phenomenon, my whole career. It's not just me. I have seen subluxation denounced as the scourge of humankind, and I have also seen a national organization launch a campaign to "Save Our Subluxation." The chiropractic profession's love-hate relationship with subluxation is illustrated every time we provide preventative care to a patient who is, well, unsubluxated. What are we adjusting for, and might we not create subluxation (however defined)? (I am just being rhetorical; I am not really afraid of that.)

My good friend, Dr. Gleberzon, and I wrote an article describing how every technique system features a "subluxation-equivalent (SE),3 some word that refers to something bad in or about the spine. I wish we had pointed out in that article that the ubiquitous emphasis on SEs had really got us chiropractors in some trouble. It does not provide for musculoskeletal problems wherein misalignment (segmental or regional) is a preferred solution, given some other constraint: congenital or acquired spinal defect, a primary muscular problem, or maybe neurological damage.

Is subluxation the scourge of humankind? Yes, except when it is appropriate. I think the chiropractic profession might be better off stressing optimal structure and function, not spinal models based on symmetry and curve-fitting models. I guess my concept of SE might work as follows:

A normal spine is one which assumes a structure that is optimally configured for desirable function, subject to individual anatomic and physiological constraints; and a subluxation is a state in which the spine does not exhibit such optimality.

Did I get it right, Dr. Pettibon?

Author's Note: As I cover meetings of the American Back Society for Dynamic Chiropractic, I would like to mention that this year's meeting will be Nov. 16-19 in San Francisco. Please contact the ABS for further information:


  1. Cooperstein R. Spinal graffiti: the rise and fall of the Harrison Spinal Model. Dynamic Chiropractic, Oct. 21, 1996:
  2. Cooperstein R. Letter to the editor on "normal sagittal spinal configuration: a desirable clinical outcome." J Manipulative Physiol Ther 1996;20(2):136-137.
  3. Cooperstein R, Gleberzon BJ. Toward a taxonomy of subluxation-equivalents. Topics in Clinical Chiropractic 2001;8(1):49-60.
  4. Winterstein J. Spinal distortion and stress reversal. Journal of the American Chiropractic Association 2001;38(11):44-45.
  5. Troyanovich SJ, Harrison DD. Chiropractic biophysics (CBP) technique. Chir Tech 1996;8(1):30-35.
  6. Troyanovich SJ. Structural Rehabilitation of the Spine & Posture: A Practical Approach. Huntington Beach, CA: MPAmedia; 2001.
  7. Curl DD. Ocular problems and their relevance. Dynamic Chiropractic, Feb. 11, 1994:
  8. Dietrich DE, Slack WJ. Scoliosis secondary to unilateral extraocular muscle paresis (ocular torticollis). Radiology 1967;88(3):538-42.
  9. Levangie PK. The association between static pelvic asymmetry and low back pain [In Process Citation]. Spine 1999;24(12):1234-42.
  10. Cooperstein R. Integrated Chiropractic Technique: Chiropraxis. Oakland, CA: Self-published; 2000.
  11. Cooperstein R, Morschhauser E, Lisi A, Nick T. Validity of compressive leg checking in measuring artificial leg length inequality. J Manipulative Physiol Ther 2003;26(9):557-566.
  12. Cooperstein R, Morschhauser E, Lisi A. Cross-sectional validity of compressive leg checking in measuring artificially created leg length inequality. Journal of Chiropractic Medicine 2004;3(3):91-95.
  13. Cooperstein R, Lisi A. Pelvic torsion: anatomical considerations, construct validity, and chiropractic examination procedures. Topics in Clinical Chiropractic 2000;7(3):38-49.

Dr. Robert Cooperstein, a professor at Palmer College of Chiropractic West, can be reached at, or by e-mail at .

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