December 2008

The physics of failure

by Dr. Mark Payne

In my last column, I revealed chiropractic's "dirty little secret." There's no hiding from it now...the word is out. We are a profession built upon the premise that structural misalignment results in bodily dysfunction. The only problem is traditional chiropractic adjustments don't do very much to change spinal structure. Sorry to be the one to break the news but it's a fact.

As long as the cat's out of the proverbial bag, let's talk about why our adjustments generally fail to produce much in the way of real structural change. Once you understand how the laws of physics sabotage your adjustments, you'll be well-positioned to start dealing with the problem.

Want to know why your adjustments don't change spinal structure consistently? The answer is painfully obvious when you consider the basic anatomy and mechanical characteristics of the spine. Most of us had some exposure to basic physical science in our pre-chiropractic education. Apparently all the chiropractic colleges just forgot to tell us how it applies to the spine.

The spine is a bony column suspended in an ocean of soft tissues. Spinal structure (posture) may be adversely impacted due to injury/deconditioning of the column, the surrounding tissues, or other structures along the kinetic chain. Once injured, the spine may adapt and compensate in numerous ways. Paraspinal muscles may weaken or become overactive. Supporting ligaments, tendons, and fascia may be overstretched or chronically shortened. Discs may degenerate under abnormal loads created by postural imbalance. Soon, patients begin to compensate for pain/weakness by developing new, often less efficient, ways to move. The body learns new motor habits and slowly comes to accept the new postural imbalance as normal. Most of this happens so gradually the patient generally has very little awareness of how imbalanced and weakened they have become.

Every day, chiropractors step into this complicated collision of cause and effect. Armed with our adjustments, we wage battle against the effects of time. The thrust is delivered in a fraction of a second. The tissue yields, segments move, joints cavitate. It feels so real, so reassuring. But it's what you don't feel that's more important. By the time your hand leaves the spine, the elastic properties of the surrounding soft tissues rebound the spine right back to its original position. Certainly, our adjustments bring real benefits to the patient. But today's question is; "Have you actually done anything to change the spinal structure?" Unfortunately, in most cases the answer is….not much. Here's why.

You probably recall the basic mechanical properties of "elasticity," "viscosity," and "plasticity" from your high school physics class. Elasticity is pretty self-explanatory. It's the tendency of matter, in this case the paraspinal tissues, to snap back once the deforming force (your adjustment) is removed. Visualize a rubber band. Viscosity describes the tendency of thick liquid substances to slowly "flow" or "remodel" over time. Think of thick motor oil, or if you're from the south, that last drop of molasses which oozes out of your biscuit onto your lap. Finally, plasticity describes the nature of semi-solid substances to also remodel over time, once the deforming force exceeds a certain "yielding point". Modeling clay for example continues to be malleable as long as the sculptor applies a certain amount of force. The thing to remember is that both viscous and plastic deformation, occur slowly over time and unlike elastic deformation, the change is permanent. That can be a very good thing for chiropractors IF we understand how to make it work for us.

All living tissues possess some combination of elasticity, viscosity, and plasticity. Tissues with higher water content tend to deform or stretch very slowly since water is a highly viscous liquid. Discs have somewhat lower water content and are consequently more plastic in nature. When our only tool is the rapid loading force of our adjustments, only the elastic tissues have time to deform and of course, they just snap the spine back to the starting point once our thrust force is removed. What then must we do in order to effect change in the viscous and plastic tissue elements? Might it be possible to improve spinal corrections by applying our corrective forces differently?

As it turns out, the only way to effectively stretch taut visco-plastic tissues is to apply continuous force over TIME. Yet, time, the very thing we need most, is something traditional adjustments can't provide. Adding simple sustained force methods to your regular adjustments has been shown to produce spinal corrections up to three times that of adjustments alone. I'll cover some basic methods in future columns. For now, check out this month's illustrations to get a feel for what I'm describing then give me a call personally at 334-448-1210 if you'd like to learn more about working with the laws of physics to correct your patients.

(Dr. Mark Payne is a 1979 graduate of Life Chiropractic College and the president of Matlin Mfg. Inc., a manufacturer and distributor of postural chiropractic products since 1988.)