It arose out of thinking about the whole problem we have with PT having evolved as a culturally specific form of health care, along with most of the others, without good biological foundation (i.e., embryology and evolution), therefore rudderless. Although I've tried to grow myself a rudder, the profession lacks such a thing collectively.
Anywhere humans have a culture, there exists "healthcare." Culturally specific forms of health care we are familiar with in the western world include:
1. manual/physical therapies: PT, chiro, osteopathy, massage (many kinds), and the multitude of techniques named after individual originators who came out of the woodwork, Rolfing, Bowen, all these..
2. medical, surgical and nursing care for life-threatening trauma and disease
3. care for emotional, mental and psychological difficulties, e.g. psychotherapy, psychiatry
Other cultures combine these three main forms in other ways. All are categories of interventions sought, instinctively, by people who are undergoing life-disrupting or life-derailing problems with their bodies or their ability to think or relate appropriately.
Humans are primates, and primate survival is enhanced by being a member of a "troop". All three of these categories represent "help" extended to an individual who seeks it from the social human "troop" in times of either overt or perceived need. One can quibble over what constitutes "true" need; however, usually the most prioritized need is the one that bothers a given individual most within a given time frame. This would include such things as the "need" to breathe, to drink if thirsty, etc. Of the array of "need" states that can be defined, many of which the individual can instinctively take care of, a few seem to be recalcitrant to self-help for some people; e.g., pain is one (defined as a need state by Patrick Wall) that looms quite large for many people who have an active and functional nervous system. Pain is a frustrating phenomenon to endure; it can cause stress, and stress can in turn worsen pain. Pain can reduce one's ability to cope in a mature manner, thus interfering with relationship. Relationships interfered with may threaten one's place in a troop, and threat like that can lead straight to anxiety - for a primate - and more stress.
When stressed, primates (including human) seek social grooming. There will always be those among us who feel best when able to access "social grooming" of some sort for pain or distress or illness, and there will always be a supply of groomers ready to help, because humans are primates. Other primates groom each other instinctively, and so would we, if we were not constrained by "culture" and laws in place to regulate boundaried contact (for good reason). Social needs blurred into biological needs have a way of making culture adapt to them. Enter quintessentially "human" primate social grooming.
Also, enter the collision between who and what humans (collectively) think ourselves to be, and who or what humans (individually) default to in times of stress or physical need - biology takes over. Enter the "professional" splintering of a nurture behavior once fueled by nature into a bunch of modern (correction - let's make that postmodern, counter-enlightened) fragmented, rigorously (or not) regulated, politically defensive turf-raiding, territory-defending groups that are operationally primate troops in and of themselves to a great extent. Some are science-based while others are thoroughly a- or even anti-scientific. They exist in relation to each other, like rail cars on a train track, their position in the train having emerged by their relation to science; they all move along (some eagerly and some reluctantly), clashing, colliding, all ultimately pulled along through time by the chugging engine of Science and Society, the caboose of anti-science bringing up the rear, linked by that primate biological troop mandate "to help" and "to serve" and restore quantity and quality of living to fellow human primates, doomed to never escape the train - unless sidelined permanently, decommissioned due to dwindled popularity or de-legalized by future social contracts. This train is not bound for glory. It is slow and lurches uncomfortably. Cars routinely collide into each other. Any individual can climb aboard anytime onto any car of choice. Individuals that belong to one car can move about the train and visit other cars, check them out.
The whole point of the interaction of human primate social grooming (the non-medical kind, the more strictly manual therapy kind), or the establishment of any therapeutic relationship, is to get the right placebo response (in the Patrick Wall sense) started. All forms of health care are therefore veiled forms of human primate social grooming, and manual therapies are more direct forms, attempts to physically elicit said placebo response.
Social grooming started out as the simple 'nurture of nature', you might say - an animal activity, i.e., mammal mothers attentively licking their pups/kittens/calves etc. Primates took it further into wider social arenas, intra-troop behavior, maintenance of relationship.
Primatologists think one of the factors that may have driven development of our big brain in the first place was that it may have come in handy for keeping track of who was who, and to keep the peace (see Dunbar's number). The initial bonding that goes on between humans (e.g. parent/child) may well need to be reaffirmed artificially once in awhile, such as when there is a period of personal drama or trauma,, chaos or growth, which may or may not include physical injury. What we know for sure is that physical injury is certain to knock one off one's tracks for awhile; how it is handled socially, therapeutically, can be/often is pivotal to good resolution. See here, and here, for old blog posts about the insula.
If that's all true, then good old, non-nociceptive/unresolved 'pain', physical and/or psychological, is a need state all right, one that may require consummatory movement on a spectrum that ranges from just practicing some creative motor output at one end of the scale, further along to active physical relating e.g., hugging/sex with a partner, way over to the far end of the social spectrum to boundaried input of a physical sort from a therapeutic 'stranger', all depending on the individual. In the latter case perhaps the bond inside the patient, their intra-psychic balance, the bond they have, perhaps with their perceived relationship to their own biological life itself, can only be restored through physical human contact, from way outside the immediate family.
I think this is probably so fundamental that everyone just ignores it completely.
There are likely to be social groomers out there who because of human belief systems, won't entertain the possibility that we evolved instinctively doing this merely because of how healthy it feels, both for the groomer and the groomee. (Manipulation is likely more of a latecomer on the social grooming scene. It has its own unique sensory charm for some, I suppose.) There are still more who insist on trying to turn (manual) human primate social grooming into something quantifiable, standardized, objectified, reproducible... something more "human" (by mechanized western cultural standards), but possibly something at the same time less "humane" (by human primate social grooming standards). Still others get the kinesthetic part, love the kinesthetic part, but refuse to try to understand such a phenomenon scientifically - they even reject it, preferring to adopt mystical explanations instead, presumably because these "feel" better. We probably all get held back by all these proclivities.
This was once a huge problem/obstacle/quandary for me.. I could barely see the outline of it and it felt awfully big, like a chasm in the fog. When I came up against it in my own thinking I just didn't quite know where to go with it, how to dissect it, deconstruct it, deal with it, digest it. I understood it but not well enough to dispel it. I felt capable of nothing but blatting it out halfbaked. It made me feel cognitively dissonant, weak in the knees. Maybe the whole faintly nauseated feeling cognitive dissonance confers is what drives PTs and other "groomers" off to once again cling to religious anti-evolutionary belief systems. The truth (and I think this is truth) kinda sucks, doesn't it? - adds no glamour at all to our profession, makes us humble, puts us in our place at the bottom of the health care hierarchy, confronts us with the probability that we mostly deal with the non-human underpinnings of physical human existence, the deeper ways that bodies and nervous systems are connected. To go there boldly means confronting the fact we are primates, I think. And that like monkeys, our various manual therapy professions, by virtue of being "hands-on", and more primally primate than others, perhaps.
Yet, when I pondered the matter from another side, as one who instinctively moved toward this type of work when I was still a child, driven perhaps by overactive mirror neurons, it feels real and honest and natural and honorable by comparison with lots of other human activity going on that is greed-based and disgusting and destructive. What I find more disgusting is when human primate social grooming is dragged down further by greed and scam and dopamemes.
Fast forward a few years and I'm still not quite sure how all this fits together, but I think this sociological/evolutionary/psychological overview deserves at least a mention in the overall consideration of manual therapy. Acupuncturist/medical physician, Anthony Campbell, wrote:
"Among primates, we are the only species that does not routinely perform physical grooming. The manual therapies provide one of the few occasions when it is socially acceptable for comparative strangers to touch another's body in a manner that approximates to primate grooming. It seems likely to me that part of the success of the manual therapies depends on this, and differences in success rates among therapists are probably related to differences in how they apply touch.(See his whole comment in "Rapid Responses" after this article, Characteristic and incidental (placebo) effects in complex interventions such as acupuncture.)
The mechanism of touch as therapy is no doubt complex but is likely to involve the limbic system (cingulate gyrus) and release of oxytocin."