The dorsal horn has a feedback loop that can be affected via sympathetic vasoconstriction and muscle spasm which stimulates again the nociceptive fibers and perpetuates the vertebral subluxation complex. The chiropractic adjustment (via stimulation of the A-beta fibers/joint mechanoreceptors and stimulation of the 1B fibers/golgi tendons) interrupts the crossing of the fibers to the anterolateral spinothalamic and spinoreticular tracts, both presynaptically and postsynaptically. Because "trauma and toxins" irritate A-delta and C fibers causing nociceptive irritation, we can understand why, neurologically, D.D. Palmer was far ahead of his time.
The "autosuggestions" component is critically important and must not be overlooked. In the text Psychological and Neural Mechanisms of Pain by Price, he states that electrical stimulation of brain structures, including the periaqueductal gray and nucleus raphis magnus, inhibits dorsal horn nociceptive neurons much more frequently than low threshold mechanoreceptive neurons. In short, this suggests that the descending inhibitory pathways are actually stronger for inhibiting nociceptive input than the mechanoreceptors, which can be stimulated via exercise, nutrition, or chiropractic adjustments. I certainly do not mean to belittle the importance of nutrition, exercise, or the chiropractic adjustment, however, I do not want us to overlook the psychological component of our patients' health. Chiropractors routinely get high marks for patient satisfaction; this is an important component to healing.
David Seaman, DC, DACBN, in his text Chiropractic and Pain Control gives excellent, detailed, yet understandable information about neurology, the vertebral subluxation complex, and the chiropractic adjustment. This text has tremendous information about why chiropractic is so important and successful.
A student recently asked me why I spent so much time on the vertebral subluxation complex at a chiropractic Motion Palpation Institute seminar. What came to my mind, when presented with this question, was the time I observed a knee surgery at a local hospital six years ago. The orthopedic surgeon and a surgical resident were going over their upcoming case; the lead surgeon said to the resident, "You can teach a monkey how to do surgery, but the important part is knowing when and why." I feel that the chiropractic adjustment is somewhat similar. You can teach a monkey how to adjust, but you need to know when to adjust, what is occurring when you adjust, why you should adjust, and when you should not adjust. We need to know about the subluxation complex because it's what we do.
Mark A. King, DC
Cincinnati, Ohio
Dr. Mark King graduated from Life Chiropractic College in 1986. He is a clinician at Mt. Lookout Chiropractic Sports & Injury Center in Cincinnati; president and lead instructor of the Motion Palpation Institute; and a coach and co-founder of Cutting Edge Chiropractic Consultants.