The Chiropractic "Chicken or the Egg" Answered

By Richard Barwell, DC

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The solidarity chant when I attended chiropractic college was one of "structure governs function." This was almost sacred ground and no one dared to tamper with this concept because without "structure governs function" as our guiding principle, the profession would lose all meaning. The concept of vertebral subluxation and nerve root irritation as the very essence of chiropractic was drilled into every student. Despite the fact that there wasn't any proof of this,1 outside of anecdotal results in patient testimonials, the profession could not be swayed from this "structure governs function" position.

I based my professional career on this chant. I recall the programs that focused on spinal position and movement, which was the same old approach with some new packaging. The presentations always started with a vertebra out of place or fixed in position, and I accepted this as the fundamental truth for chiropractic. Then my troubles started - I started thinking! Afterward, I really don't know how many technique courses I took, but in each one I heard that their approach was the best or "only" technique, and I began to realize that there had to be more to what was really going on when we adjust a patient.

I noticed that no single technique was the answer and that sometimes when I changed my technique, I got better results. I also noticed that in failing to develop a scientific understanding of what was really happening with an adjustment, we ended up allowing the technique masters to define chiropractic. It seems that the vast majority of chiropractors used what became known as "diversified technique" (before someone took on the name as a specific technique), which just meant the use of a variety of different methods of adjusting as the need required. The majority of techniques were based on "structure governs function." Change the structure; that is, alter spinal positions, which allows the nerve root to be free of pressure and voila´ - good results! X-ray and changes in spinal curves were used to justify this concept.

Trouble in River City on at least three fronts. First, even after 114 years, there is no proof that spinal nerve root pressure exists. (Yes, I know the nerve root is sensitive.) Second, this still doesn't explain how the light-touch techniques get great results. Third, can someone please explain how drinking a gallon of diet soda knocks a vertebra out of position?!

When we abandoned the "bone on nerve" theory, we substituted the "vertebral fixation" theory, and did nothing to explain what was really going on. Today, the world of neuroscience provides an answer, and while it doesn't support the vertebral subluxation theory, it certainly does provide a beautiful science to support the power of the adjustment to alter neurological function.2 The first step is to understand that "function governs structure"! As I have presented the foundations for this around the world, I have heard the old timers muttering the chant under their breath, hoping to block my inferred heretical idea.

There have been two papers published on the power of the adjustment to effect change in brain-wave patterns3-4 and there are more to come. Today, neuroscience is able to explain the importance of the ability of the nervous system to adapt to stressors and then recover.5 The research over the past 40 years done by the bio/neuro-feedback community has provided the clear role of a balanced nervous system when discussing good health.6 The loss of the central nervous system's ability to adapt and recover has now become the critical issue in maintaining good health. When neuroplasticity is lost, a neural pattern develops. The latest research shows that the chiropractic adjustment can alter these fixed patterns and thereby allow the CNS to move toward an improved balance.

The bones and joints are a passive system (do nothing on their own). The muscles are the active system (their action creates all body function including: joint movement, digestion, excretion, elimination, respiration), but depend on information to act. The central nervous system is the central organizing authority.7 By continuing to focus on the bones, joints and the muscles (musculoskeletal approach or structure), we have been dealing with secondary and tertiary responses.

Our fundamental understanding has been somewhat correct, but our concept of addressing structure as our primary mode of care is wrong. The reason that the chiropractic adjustment is so effective is that it can alter the neurological response through applied sensory stimulation. The large amount of sensor receptors in and around the spine has made this a good access area in which DCs can introduce a pattern interrupt.

What I find so exciting is that this slight shift in the concepts of chiropractic only strengthens our position and broadens the scope of our practice. No longer are we limited to pain-based practice or one technique. No longer are we outside the accepted approach in health care with an outdated theory of vertebral subluxation and nerve root pressure. Today, we have a firm grip on the neurological foundation of chiropractic with evidence to support the effectiveness of the adjustment to alter CNS function. With the firm understanding that "function governs structure," we can now view our role in the health care field as "functional neurologists"!


  1. Bolton PS. Reflex effects of vertebral subluxations: the peripheral nervous system. An update. JMPT, February 2000;23(2):101-3. Prof. Bolton, Faculty of Medicine and Health Sciences, University of Newcastle, Callaghan, Australia writes: "The traditional chiropractic vertebral subluxation hypothesis proposes that vertebral misalignment causes illness, disease, or both. This hypothesis remains controversial."
  2. "Sydney Researchers Explain How Stress Can Make You Sick."  Science Daily; study published in Journal of Experimental Medicine, Dec. 5, 2005;202(11):1-13.
  3. Barewell R, Long A, Byers A, Schisler C. "A Four Case Study: The Effect of the Chiropractic adjustment on the Brain Wave Pattern as Measured by EEG." 2005 Sherman International Paper and Research Symposium.
  4. Haavik-Taylor H, Murphy B. Cervical spine manipulation alters sensorimotor integration: a somatosensory evoked potential study. Clinical Neurophysiology, 2007;118:391-402.
  5. Sapolsky R. Why Zebras Don't Get Ulcers, 2nd Edition: An Updated Guide to Stress, Stress-Related Diseases and Coping. W.H. Freeman, 1998.
  6. Othmer S, Othmer SF, Kaiser DA. "EEG Biofeedback: A Generalized Approach to Neuroregulation." Applied Neuropyhsiology & Brain Biofeedback, 1997.
  7. Lockeart RD, Hamilton GF, Fyfe FW. Anatomy of the Human Body - The Nervous System. Faber and Faber (limited):264.

Dr. Richard Barwell graduated from Canadian Memorial Chiropractic College with honors in 1964. He has been in clinical practice for 31 years and is the founder and president of the Chiropractic Equity Offices Inc. program.

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