Asking Why

Evolutionary Reasoning and Manual Care

Barrett L. Dorko, P.T.

In 1990 I wrote an essay about a young boy who’d been sent to me with an acutely painful neck. After turning it quickly left he experienced a great deal of pain and found that any attempt to return it toward the front felt even worse. I described the boy’s dilemma and then wrote: “In Arlington Virginia The Old Guard marches before the Tomb of the Unknowns. Its members are remarkably the same in every respect. The precision of their movement is matched by the perfect stillness of their erect postures. They seem to embody composure and stability. There is something about a collection of humans moving and appearing as one that fascinates us so that we support them monetarily and emotionally. Most governments in this world have institutionalized such groups and use them as an exemplar of their tradition and power.”

The boy’s doctor had called and requested that I manipulate him. He felt that the deformity was the problem and wanted me to quickly reduce it. He said, “Maybe you could do some manipulation.”

I wrote: “But Paul doesn't care much about straightening out his neck. He just wants the pain to stop. He's been cold for 3 days and has asked repeatedly to lie in a warm tub. He is making absolutely no effort to return his neck to a neutral position.  As a fan of human precision and erectness, I feel an urge to coerce Paul back to a straightened position. I want very much to see him facing forward, composed and ready for movement, to make him look like a member of The Old Guard. I am in fact licensed to push him in that direction.”

Louis Gifford states in An introduction to evolutionary reasoning: diets, discs, fevers and placebo (Topical Issues in Pain Volume 4) “Good reasoning when applied to the understanding of any presenting observation, or condition involves two perspectives: An evolutionary perspective asks the simple question “Why?” and a more traditionally scientific perspective asks the question “What?” or “How?” about structure and mechanisms. The ‘what and ‘how’ reasoning perspective is termed a proximal, or near explanation of cause for a given observation. In medicine, proximal explanations address how a body works. Evolutionary or ultimate explanations show why humans, in general, are susceptible to some diseases and not to others (See Nesse & Williams Why We Get Sick: The New Science of Darwinian Medicine Vintage 1994).” It is important to note that proximal and evolutionary reasoning are not alternatives; both are needed to understand our body’s behavior.

Evolutionary reasoning is not commonly used in clinical science but here I want to point out what effect it may have on the provision of manual care. It suggests we divide bodily response to trauma or disease into one of two categories-defects and defenses. Defects are those processes or behaviors that reveal the body’s weaknesses; they are the result of the disease process and are present without any particular utility. Defenses serve a purpose. They promote a change toward health and homeostasis. If we categorize our findings upon exam in this way, we are guided toward care that seeks to reduce the manifestation of the defect and leave the defense to do its job, that is, preserve our species. If we mistake one for the other care will be ineffective, and clearly runs the risk of becoming counter-productive. 

Gifford goes on to describe the classic “lateral shift” often seen associated with lumbar and lower quarter pain. In such a case the shifting of the torso away from the symptomatic side and the loss of lumbar lordosis has been described as a response to intervertebral disc migration, specifically the “unloading” of the side containing the bulge. This is proximal reasoning. Evolutionary reasoning would consider whether the observed behavior was useful or not, and if useful, in what way toward which tissue. The proximal reasoning regarding lateral shifting ignores the fact that this posture does nothing to help the disc (See Does plate fixation prevent disc degeneration after a lateral annulus tear? Moore et al Spine 19(24) 2787-2790). Since immobility doesn’t help the disc, it doesn’t follow that a tear in the disc would lead to this behavior. If the immobility we see upon examination is instinctive and thus deemed defensive, efforts to extinguish it with manual coercion or instruction must be considered unreasonable.  

I heartily agree with this quote from Gifford: “Any threat to the nervous system is a potential disaster for the future efficiency of those afflicted. Far better, and more efficient to, whenever possible, adapt to a new posture that protects the nervous system, than to injure the nerve and suffer the consequences of neuropathy.” Understood in this way, lateral shifting is more appropriately interpreted as a protective action in response to abnormal neural dynamics. It is a defense, not a defect, and it shouldn’t be extinguished. Without question the most sensitive and vulnerable of our structures is the nervous tissue and restricted movement of all sorts, painful or not, might reasonably be considered a natural consequence of some compromised neural mobility. A heightened awareness of our brain’s interest in the ability of the nerves themselves to move freely and perpetually acquire adequate nutrition would lead us to conclude that restricted range of motion would be the patient’s first defense against nervous irritation and that this restriction is not truly the problem but merely one perfectly reasonable solution. Trying to rid the patient of their restriction with stretching that ignores the underlying reason for its presence (abnormal neurodynamics) is very likely to accomplish nothing if not actually worsen the symptoms, and, if willful or passive stretching does manage to reduce the symptoms I assume a good deal of luck was involved. 

In the essay The Old Guard the referring physician had only reasoned proximally when he suggested that I work to reduce the deformity somewhere in the cervical spine, and had I given in to my inclination to coerce patients I would have pushed the boy toward the center as I had thousands before him. I didn’t. Instead, I allowed the boy to move as he wished. It wasn’t much to see, but it produced the warmth and relaxation he sought. I wrote of his care: “… many failures with coercive technique have taught me that Paul knows a lot more about what to do than I. If I accept his resistance to movement toward the center as appropriate, he will show me the path out of trouble.”

I can see now that my reasoning was evolutionary, though I was at the time unfamiliar with the term. I saw the immobility as a defense, not a defect and I used the instinctive muscular activity that was evident to palpation, also known as ideomotor activity, to move him in a fashion that moved the maladaptive autonomic response toward normalcy- “Paul’s posture wasn't much changed after the first visit; his shape was the same. But he was smiling, he was warm, and he felt real sleepy. If we suppress the urge to make him look better on the surface, his recovery will proceed in its ideal time.”  Similarly, Gifford writes: “We tend to think that we are in a healing profession and the pressure is on us to provide a cure. Evolutionary reasoning invites a shift of thinking to consider that this flexed and deviated posture in the patient example, might be a very adaptive response and one not to be meddled with? Would you ever consider saying to a patient: “Don’t worry about your flexed and shifted posture it’s very useful and protective at the present time - it will get better as your problem gets better, and at the appropriate time I will help you to gradually overcome it. If we attempt to correct the way you stand and move too quickly, we may actually prolong your problem.”

Asking why any movement dysfunction is present may often lead us to conclude that manual coercion is unreasonable. To put it simply, when the therapist pushes upon the patient in an effort to reduce instinctive muscular response or to correct bony alignment the adaptive response is being inappropriately extinguished. Remember that the concept of defense in evolutionary reasoning isn’t the simple guarding normally assumed to account for persistent muscular contraction; this activity is more accurately considered the beginning of a corrective maneuver. It has been my experience that, when amplified, muscular activity concurrent with restricted movement or supposed aberrations of ideal posture will lead quite rapidly to a reduction in the sympathetic increase known to complicate and perpetuate painful conditions. This is the basic idea behind the use of Simple Contact, the method of handling I teach and employ. Clinically the patient will report a warming sensation while a palpable reduction in muscular resting tone will become evident. Ideally, manual care reverses the effects of the defect (sustained sympathetic tone) while simultaneously enhancing the body’s naturally occurring defense (ideomotor activity). At the present time, manual care rarely accomplishes either of these tasks.

The combined use of proximal and evolutionary reasoning makes the most of our knowledge of anatomy and physiology while displaying an appreciation for our genetic inheritance. It leads us to reconsider the coercive methods often imposed upon others and instead allows us to witness the naturally occurring movement toward pain relief that is a consequence of instinct. This would revolutionize pain management and distinctly alter our profession’s place within that field.