Ecosystem Thermodynamics as Applied to Public Health through Chiropractic

Ecosystem Thermodynamics as Applied to Public Health through Chiropractic


The human CNS functions to monitor internal and external energy and information flows and interpret their meaning relative to personal resource state for the purpose of successful adaptation. Chiropractic has always been a profession focused on the ability to self regulate and adapt through an optimally functioning CNS. The field of Ecology has always had a focus on the flows of energy and information through natural systems and how life expresses itself as a result of orienting towards those flows. Since the origins of chiropractic in 1895, the field of ecology has made a great many advancements. Currently there is an interest in expanding the field of ecology into the study of systems developed by humans and how they interact with non-human developed ecosystems. In turn the field of Public Health is interested in the ways human designed ecosystems can influence population health.

As the original chiropractic principles were developed from observation of natural laws at a time when the science of ecology was in its infancy, and the founder of the profession, in his last – posthumously – published book, first discussed principles of a science known then as bionomics which would become ecology over time, an exploration of the foundational concepts and principles of chiropractic through the lens of modern ecological principles is long overdue. This paper explores principles of ecology, thermodynamics, and other fields as they relate to the basic premises of chiropractic, its practice, and their intersection with personal and public health.

The intersection of Ecology and Human Health – an Important Perspective for a Modern Time

Perspectives on human health have evolved significantly over the last century, shifting from a view that health outcomes were genetically determined,1 towards a more nuanced view that integrates genetic, environmental, and social factors as the multifactorial drivers of individual and social health outcomes.2 The emerging paradigm for public health incorporates a focus on the creation of social and environmental conditions that are conducive for optimal health outcomes.2 Perhaps the recognition of a need to create social structures and an environment with qualities that result in a greater likelihood of quality health decisions by citizens has arisen from a modern take on genetics that is is more probabilistic than determinant.3 The question of whether or not humans have free will from a behavioral psychology perspective is another factor that may be playing a role in this increased focus on crafting human environments that result in healthier behaviors.4 If much of human behavior is probabilistic, then understanding the ecological factors that contribute to healthy behaviors will be essential for influencing society towards optimal public health outcomes. An exploration of how the human CNS perceives, interprets, and adapts to environmental and social conditions, and how those capacities may be restored or enhanced in a way that results in a higher probability of healthy behaviors, would be a valuable addition to the discourse on human ecology and public health.

The link between Ecology and Chiropractic’s Origins – The study of energy flows through living systems

When DD Palmer introduced chiropractic in the second chapter of his posthumously published last book, he first described the science of ecology, or bionomics, and the intelligent forces of adaptation present within living things.5 Bionomics is an alternative description of the field of ecology with the earliest known use in 1888, which would place it contemporary with DD Palmer.6 Ecology studies the flows of energy through complex living systems. The foundational principles of chiropractic are concerned with the same. The flow of energy and information throughout the human system and how that flow relates to our ability to adapt to the world around us is a major focus of the Chiropractic Textbook by Stephenson.7

How the flow of energy through living systems is congruent with the 2nd law of thermodynamics was a major question in the middle of the last century, with such minds as Erwin Schrödinger and Ilya Prigogine studying the problem.8,9 The solution is that living things are dissipative structures that develop and maintain organization through the transformation of energy gradients from lower to higher levels of entropy.10 The emergence of self replicating organized structures that led to the evolution of life on earth may even be the result of this process.11

The problematic terms of subluxation, innate and vitalism

The first principle, or major premise of chiropractic, states that: Universal Intelligence is in all matter and continually gives to it all its properties and actions, thus maintaining it in existence. The portion of that intelligence that resides within individuals, maintaining their existence, is termed Innate Intelligence. The Chiropractic Subluxation has been defined as an interference with the transmission of mental impulses, with mental impulses being comprised of regulating information sourced in Innate Intelligence.7 Early chiropractic thought was a mixture of leading edge science and 19th century American metaphysical culture. DD Palmer was an integrative thinker and sought to move beyond the dualistic perspective of a separate mind/body in his new profession.12

The metaphysical nature of many of Palmers concepts contain tones of vitalism which has been problematic for the profession over time. Vitalism carries with it a great deal of historical baggage. Echoes of a magical past where spirits animated matter, and angels and demons were forces of power in the physical world color our perception of the term to the present. This link to supernatural causation gives the opponent of any philosophy with vitalistic underpinnings an opening to proclaim that same philosophy as pseudoscience. Vitalism has had different meanings over the centuries. From a pre-rational perspective the approach to vitalism is one that claims a vital force comes from outside the body and animates it with life. From a post-rational perspective the vitalistic approach is one that views living systems as a nested hierarchy of wholes, which cannot be separated from body, mind, spirit, self, society, and culture.13

The major claim of vitalism, post Cartesian Split, is that the origin and phenomena of life are dependent on a force or principle distinct from purely mechanistic chemical or physical forces. Intuitively this idea is appealing. Life is a mysterious and ephemeral thing that cannot be quantified. While the personal beliefs of individual practitioners are their own concern I do not believe vitalism is a philosophy essential to understand or explain the basic chiropractic principles. The sciences of biophysics, thermodynamics and ecology have advanced enough in the past 100 years to elucidate them without appealing to supernatural causation.

Thermodynamics as Link Between Chiropractic and Ecology

At its core the chiropractic subluxation is an interference in the flow of energy and information somewhere in the human CNS, a complex biological system. As ecology is also concerned with the flows of energy and information I will first discuss some basic ways energy flows through non human living systems.

The second law of thermodynamics states that the total entropy of an isolated system always increases over time. Entropy can be thought of as a lack of order or predictability; a gradual decline into disorder. So the idea that a sperm and an egg would unite and develop into an infant that grows into an adult human being appears to contradict this law, until one recognizes that living systems are open systems, meaning that energy can flow through them. Open systems can increase in order and organization by transforming energy gradients from lower to higher entropy. The energy gradients that living things on earth transform are the energy from the sun and the heat and chemical energy from vents on the ocean floor.10

Procession of Evolutionary Complexity as Solution to the Thermodynamic Imperative – Plants as Dissipative Structures Augmenting the Water Cycle

The sun is the primary source of energy for life here. Of the solar energy directed towards the planet 51% actually enters the biosphere. Of that 51% about half drives ocean currents and winds, most of the other half goes towards evaporating water that falls back down to earth as rain. Only 0.1% is consumed as metabolic energy for living things. The activity of that 0.1% is critical for the behavior of the remainder for several reasons. One, without life on earth the amount of water here would gradually be reduced to zero. Free hydrogen, being extremely light, can escape earths gravity and drift off on the solar wind. much of life sequesters oxygen from carbon dioxide, allowing it to bind with free hydrogen to form water. This release of Oxygen also generates ozone which prevents water vapor and methane gas form having their hydrogens removed by intense ultraviolet light. Life is also critical for maintaining a stable temperature on the planet, which is important as the amount of solar energy the earth receives has increased 25% since life beginning.14

The organization of life is adaptive in a successive manner. It evolves as conditions change, it does not remain stagnant. Thermodynamics is one driver of that evolution.10,11,14,15 Most visible and ultraviolet light from the sun is not absorbed by pure water. But those visible wavelengths are absorbed by organic life. Chlorophyl absorbs light best at wavelengths between 400 and 700. Phytoplankton absorb light best at wavelengths of 310-400, which is a much higher energy wavelength. This higher energy light was more present early in our planets history when life was dominantly marine and simple in comparison to its current expression.

As conditions on the planet shifted, life adapted in a way that generated larger number of species with complex interactions between each other that acted as further evolutionary drivers. What is fascinating is that the overall trend appears to favor the dissipative capacity of the whole system rather than choosing one species as a favorite and allowing it to evolve independence from the others. We can see this exemplified by the evolution of photosynthetic processes. 90% of the energy a plant uses goes towards evapotranspiration, but only 3% of the water transpired is needed for photosynthesis. Most plants can grow normally even in 100% humidity conditions where evapotranspiration is effectively zero. Some plants have evolved more efficient photosynthetic processes: CAM and C4 photosynthesis, but these are used by a single digit percentage of plants despite having evolved 32 and 9 million years ago respectively. The CAM and C4 plants are succulents and grasses. They are well adapted to dry environments. Their adaptation to use less water emerged from the need for a more water efficient plant to spread pioneering life to inhospitable biomes, not to increase energy efficiency as its own end. The thermodynamic driver of entropy production is primary in the function of living things and their evolution.14

To quote Karo Michaelian – “All irreversible processes, including living systems, arise and persist to produce entropy. This is not incidental, but rather a fundamental principle of Nature. Excessive transpiration has not been eliminated from plants, despite the extraordinary free energy costs, precisely because the basic thermodynamic function of a plant is to increase the global entropy production of the Earth and this is achieved by dissipating high energy photons in the presence of water and thereby augmenting the global water cycle.”14

Thermodynamics and Animal Life

As 95% of the organic biomass on the planet is plants using standard C3 photosynthesis, and no doubt a large portion of that 5% remainder is C4 and CAM plant life, the direct thermodynamic dissipative contribution of animal life must pale in comparison to plants. Yet complex animal life emerged all the same. Because animals move and have shorter life spans than many plants. By carrying seeds on their fur and in their digestive tract, through defecation and decay, they are vectors for plant reproduction which augment the fertility of landscapes, increasing the amount of territory amenable to plant life. By moving and dying, animals become a tool for the reproduction and spread of plant life around the globe. The development of movement and the need for a structure to manage it is what set the stage for the future development of chiropractic.14

“In light of the nonequilibrium thermodynamics by I. Prigogine, the autonomic nervous system as a whole may be viewed as a dissipative structure progressively assembled in the course of evolution, plastically and rhythmically interfaced between forebrain, internal and external environments, to regulate energy, matter and information exchanges.”12 “…the autonomic nervous system as a whole may be considered a complex structure which originated and became organized in the course of evolution by the progressive assembly of discrete neuronal dissipative structures. The main functional role of the autonomic system as a whole is that of inducing, maintaining and regulating ordered exchanges of matter, energy and information within and among its environments, which are the forebrain, the fluid matrix or internal environment and the external environment. Because of its inherited plastic and rhythmic properties, stimuli arising from these environments may in turn contribute to the structural and functional organization of the autonomic nervous system.” Recordati17

All organisms have some sort of information and energy processing ability. The drive to increase entropy production, ie increase energy processing capacity in living organisms, resulted in greater information processing requirements. For unicellular organisms that ability may come from surface receptors. For multicellular organisms that ability might arise in a number of ways.15 It appears as though plants process information in parallel distributed processes rather than in a single localized processor like animals. Plants may do this as a colonial organism with more than 15 different senses, using swarm intelligence and biological quantum computation.16 Almost all animals use a central nerve system to handle the information processing necessary to monitor energy flows into and out of their systems.15

Animals that are mobile devote a large portion of information processing ability towards managing movement. While the number of neurons associated with the motor cortex, proprioception, and cerebellar processing, the how of movement, is quite large, it doesn’t come close to representing the total processing power devoted towards movement. Adding in the the number of neurons representing the why of movement makes the total quite substantial. Movement must be purposeful, which means integrating movement with the sense making, meaning, and motivational regions of the brain. Animals must synchronize their level of movement intensity and direction to the level of energy available for their consumption in environments with a wide range of safety levels.

In order to adapt to variances in safety and energy availability the human nervous system has two major thermodynamically driven divisions: the sympathetic and parasympathetic divisions of the autonomic nerve system. I am ignoring the enteric nerve system for the purposes of this paper as it is not essential for describing the relationships between chiropractic, ecology and public health.

The sympathetic division is primarily focused on adaptation to exteroceptive stimuli, incoming information from the external environment. It developed to synchronize us with the daily and seasonal cycles of energy availability. It’s first activation is at birth. other predictable moments of sympathetic activation in mammals are upon waking from hibernation, and waking in the morning after an evening of restorative sleep. The sympathetic system is focused on energy mobilization and the ramping up of metabolism in response to external demand.

The parasympathetic division is active when the body is least likely to require a response to the external environment. It is activated upon entrance into hibernation, during sleep, fasting, diving, controlled breathing, recovery after stress or exercise, and grooming. What we see is a decreased level of activation with the focus on the restoration of homeostatic rhythms, the organizing, connecting ,and harmonizing to self. The organism disengages from the environment and vagal tone to the heart increases. Proprioceptive input dominates the information processing of the parasympathetic division. It is governing the thermodynamic regulation of energy exchange within self, between the various systems of the individual human ecosystem.

The investment of energetic resources in the pursuit of replenishing energetic stores, while energy is available externally, is essential, as is the investment of some of that energy towards the restoration of internal balance. The process of living is essentially the management of energetic resources so as to be active when our preferred energy sources are available, and resting in a safe place when they are not.17

It is this ability to dynamically shift between autonomic divisions in response to consistent natural cycles of energy availability, internal cycles of metabolic demands, and external adaptive challenges that allows living things to meet the thermodynamic demands of life and act in the most adaptive manner within their ecological niche. This ability to shift between divisions can be influenced by the environment and experience, as neurologically governed organisms have the capacity to learn and fine tune their adaptive responses to the environment based upon anticipation from previous demands. However, this ability to learn also means it is possible to so strongly reinforce a frequently used pattern or strategy that it becomes dominant and employed in situations where it is maladaptive. PTSD is but one example of this negative aspect of neural plasticity and conditioning.18

In humans these divisions interact with the prefrontal cortex and the remainder of the CNS to govern the adaptive responses and express the creative nature of the individual. The activity of the CNS modulates the activity of the PNS in very complex ways in order to optimally adapt the individual to their current environment and plan for the future if possible. The Prefrontal cortex is the conscious region for future planning and the intelligent regulation of thought, emotion, and behavior. This region is rapidly down regulated in times of stress by norepinephrine and dopamine, which has been known to contribute to maladaptive behaviors such as drug addiction, smoking, consumption of alcohol, and overeating.19 Groupings of subconscious brain regions known as the emotional motor system work together to perform such tasks as setting muscle tone, generating postures, and sensory experiences in a manner that enables us to act effectively in a variety of settings ranging from existential threat to reproduction.20

Evolution Driven Neural Perspectives

“There is a tendency to try to understand the function of neural circuits through analogy between nervous systems and computers. Whilst there is no doubt that analytical tools from engineering have been enormously beneficial in understanding signal processing within neural circuits, when considering the evolution of these circuits such approaches can be misleading. Brains are not designed but evolve ‘blindly’ through selection. Brains cannot be optimised as easily as machines: as nervous systems evolve they cannot disconnect the wires and ‘start over’. This means that solutions are constrained by history, and in some cases may be suboptimal.” Jeremy E. Niven and Lars Chittka 21

Reptiles and mammals have a historically adversarial relationship. Mammals are higher up the evolutionary tree and as such both transcend and include aspects of the neuronal architecture of the reptilian autonomic nerve system. The mammalian vagus nerve is a great example of this. It is comprised of two divisions. One is phylogenetically older, inherited from reptiles, unmyelinated, active during times of inescapable or overwhelming stress, and is responsible for dissociation from a stressor. The other emerged phylogenetically with mammals, is myelinated, and likely developed as a method for mammals to communicate cues of environmental safety or danger with each other. The internal auditory ossicles of mammals are separate from the jaw, allowing them to perceive a different range of sounds than reptiles. This allowed mammals as a group to communicate danger signals in the presence of reptiles without giving away their location to those same predatory reptiles.22

This creates a broader range of adaptive possibilities for mammals. The phylogentically newer division of the vagus has been termed “the social vagus” because of its role in social interaction. It governs the muscles of vocalization, listening, gesture, and facial expression and it’s tone is developed through social conditioning in infancy through maternal and paternal bonding and other social interactions. The older division governs the freeze or withdrawal response and is activated in times of overwhelming or inescapable stress. In reptiles it slows metabolism so effectively that some reptiles can achieve a state of dormancy approaching death, which is an effective survival strategy for reptiles. In humans this response can occur in varying degrees during extreme trauma or chronic long term stress. In the long run this can lead to emotional disorders such as depression or PTSD.22

As the social division of the vagus evolved most recently, its neural circuitry is the most desirable, and it should be the dominant strategy employed if at all possible. However, more primitive adaptational strategies will often become the default in the absence of the stimuli or resources required to activate more recently evolved strategies. Without the proper social cueing to develop high levels of tone in the social vagus, the human infant will default to lower level strategies. Early developmental environments where the infant receives an inadequate level of attention, play and comfort from its parents, will develop a poorly regulated autonomic system. This might happen in the case of post partum depression, in the event of a mentally ill parent or caretaker, or an abusive childhood environment. Vagal tone can also become poorly regulated in adulthood after extreme adverse experiences such as severe or prolonged trauma. It is critical that the human being as a social ape receive adequate social stimuli that cues safety and access to resources in order to express optimal health.22

These different divisions of the autonomic nerve system each represent different perceptual states. Someone with dominant primitive vagal tone will tend to see the world through a defensive lens. The ability to rapidly shift between the various perceptual states available through the autonomic system is critical for accurately perceiving and interpreting the environment, an essential for effective adaptation. These states may also be associated with groupings of adaptive movement strategies.

Human Movement Patterns

Another characteristic of the human CNS is related to its large size relative to the birth canal. Fully mature, the human CNS could not pass through, so humans are born developmentally premature compared to many other large mammals. As a result we are born with immature musculoskeletal systems that functionally mature over a period of years after birth. This occurs through reflexive co-activation of opposing muscle groups that create joint stability locally and generate power for movement from those stable points globally.23

These muscles groups have been been categorized into a Systemic Local Muscle System (SLMS) and a Systemic Global Muscle System (SGMS). The muscles of the SLMS are deep, providing inner support and control of the axial skeleton and around the body’s centre of gravity. They create a stable base of support that allows for effective and powerful movements of the larger and more superficial SGMS. They also require adequate sensory input and output to generate optimal movement function. In situations of reduced proprioception, i.e. reduced focus on interoceptive information flows, they have a tendency towards hypotonia and atrophy. They are also less active in times of pain, injury, fatigue or stress.24

In times of stress the SGMS has a tendency to dominate movement strategies, leading to poorly controlled movements that increase injury risk and lead to musculoskeletal dysfunction. This dysfunctional state most often manifests as decreased SLMS activity and increased compensatory SGMS activity. Josephine Key noted that in spinal pain populations there is a tendency for two main forms of basic muscle tone: “those who have ‘lower tone’ and are ‘looser’ with more of a tendency to antigravity collapse, and those whose tone is more hyperactive with general tightness, tension and stiffness.”.24

These muscle system imbalances lead to common movement dysfunction patterns. The primary movement dysfunctions involve a sagittal shift of the pelvis forward or backwards. These two patterns have been described as anterior or posterior pelvic crossed syndrome, APXS and PPXS. In PPXS the overall neuromuscular system is more switched on with an overactive SGMS leading to postural dysfunction with high NMS tone. In APXS the general neuromuscular system is more switched off, both SGMS and SLMS, but with patchy over-activation of the SGMS, leading to dysfunctional posture with low NMS tone.25

As both of these basic postural dysfunction syndromes have a characteristic presentation, with postural distortions and levels of tone that give the appearance of two differing defense strategies – the APXS has lower tone with a posture that hints towards withdrawal as a defense strategy, while the PPXS has higher tone with a posture that hints towards a more aggressive defense strategy, it may be that they are providing a window into the dominant division of the vagal system in that individual during times of stress. If this is the case, then monitoring overall NMS activity and postural muscle function would be a measure of how effectively the individual is adapting to their environment thermodynamically. Access to the social division of the vagus indicates an interoceptive dominant focus allows the restoration of order and functional balance in a thermodynamically efficient way that is viable for longer periods of time. A decrease in access to the social division of the vagus indicates exteroceptive focus, externally oriented energy expenditure and progressive decrease in internal organization over time, which is thermodynamically untenable once a certain level of systemic instability develops.

Adaptation & Resilience

A primary feature of the human nervous system is its ability to learn based upon prior experiences. Just as the nervous system can be conditioned to have a healthy level of social vagus tone that inhibits sympathetically driven perspectives and strategies, it can be conditioned to be driven by more primitive perspectives and strategies. The question of whether or not this is adaptive or maladaptive depends upon the environment the individual must adapt to, and how much flexibility they retain in their nervous system for shifting to higher level strategies when environmentally appropriate. Over time the appropriateness of our strategies determines out level of resilience and reserve.18

Humans are nonlinear complex adaptive systems. These systems are characterized by feedback loops, spontaneous robust order, emergent organization, and numerous interactions, which have the capacity to change and learn from experience, and react to external perturbations in a manner which may or may not be proportional to the size of the perturbation. We enhance our adaptive capacity and survival value by learning from prior experiences. Stressors are factors that push an organism away from a baseline state towards one of lower utility. Stressors may enhance the resilience of an organism, or they may decrease the resilience of an organism. This difference is dependent upon many factors. One stressful event that does not exceed the adaptive reserves of an organism is unlikely to prevent the organism from returning to healthy baseline. However, one that highly taxes the reserves of an organism may cause its baseline to shift towards one of lower utility, or adaptive potential.18

Oken, Chamine and Wakeland, describe resilience in response to stress is described in terms of attractor basins with varying depths. For example: in the case of a healthy state vs PTSD, the higher resilience state would be represented by a very deep basin for the healthy state and a very shallow basin for the PTSD state. It would require a great deal of stress to push the system from the healthy basin into the PTSD basin. In a lower resilience state the two basins are both shallow, so very little stress is required to tip the system into the PTSD basin.18

Exposure to small stressors in the presence of resources and recovery time deepens the healthy basin and increases survival value, or resilience. Repeated chronic stressors that tax the body’s resilience will gradually decrease the depth of the healthy basin and decrease survival value. Resilience is a measure of how quickly the body is able to return to baseline. Some factors that make the experience of an event more stressful are: novelty, unpredictability, threat to one’s ego, or sense of loss of control. The more of these factors that are present simultaneously, the more resilience will be required to adapt to the experience, and the more challenging it will be to recover back the healthy baseline afterward.18

This cost to the system of attempted return to healthy baseline in the face of chronic stressors has been termed allostatic load. This allostatic load represents the application of energy by the sympathetic system towards adaptation. The body is not designed to deal with exposure to chronic repetitive stressors without adequate time and conditions for the parasympathetic system to engage and restore internal harmony. Many of the chronic diseases of modern lifestyle: heart disease and type II diabetes for example, could be considered diseases of lost resilience due to chronic energy expenditure towards exteroceptive challenges. The chemistry of the stress response is damaging to the organism if prompt return to baseline does not occur. The epidemic of modern chronic lifestyle illness could be the result of the failure to restore baseline harmony to the system.

Stated in thermodynamic terms, chronic illness could be the result of a gradual decline in the ability to transform incoming energy gradients through a loss of internal coherence and systemic organization. The ability of the individual to appropriately allocate information processing resources to exteroceptive or interoceptive flows as required, through the highest evolutionary strategy available, is essential for maintaining a high degree of resilience and adaptive potential. In chiropractic terms, what effects might a chronically exteroceptive dominant state have on the spine?

The Vertebral Subluxation

This exteroceptive dominant state, leading to alterations in neural tone, postural dysfunction, and decreased systemic resilience, leads to predictable change in spinal function in the short term which lead to structural changes over time if harmony is not restored. These spinal specific changes may be occurring due to the raised threshold for proprioceptive information in sympathetically driven states as described by Recordati.17 The exteroceptive focus coupled with this raised threshold on interoceptive information flows may be resulting in the crude movement strategies described by Josephine Key, which then lead to the following predictable alterations in the spine.24,25

* Thoracic dysfunction that begins as functional stiffness that transitions to structural stiffness
* General/regional loss of extension through spine
* Changes in normal spinal curves
* Variable segmental and rib loss of extension, rotation and side bending in thoracic region.
* Stiffness in transitional zones where the function of the spinal column changes. ‘‘These ‘key regions’ are usually the place where the spinal column suffers first.

The relevance of the specific types of spinal dysfunction described above to chiropractic practice should be plainly apparent. They describe the most common types of spinal dysfunction that are the focus for analysis and correction by the vast majority of chiropractic practitioners. Whether or not these areas of spinal dysfunction can be described as chiropractic subluxations is difficult to ascertain as the definitions for what that constitutes seem to shift in their specifics and causative models over the years. The holistically oriented subluxation described in Stephenson’s Chiropractic Textbook is very different from the mechanistically oriented vertebral subluxation complex that describes the subluxation as part of the spinal degeneration process.

I would prefer to describe the actual subluxation entity as a maladaptive exteroceptively dominant central nerve system state, and it’s manifestations within the vertebral column as sequelae. These sequelae express in a number of ways throughout the spine which allows for the inclusion of other subluxation models that are valid within their own context. This model, which I call the Thermodynamic Subluxation model, seeks to include and transcend the various other models in a way that allows for the advancement of the concept as a whole, while still retaining it’s original character.

It appears as though the exteroceptive focus associated with defense physiology results in a biomechanical state of being requiring less internally oriented information processing capacity, but utilizes crude motor strategies that lead to dysfunction and degeneration if present for long periods of time. As interoception includes information about all internal processes, not just proprioception, a long term exteroceptively dominated state would be expected to cause dysregulation of organic processes also. This model is absolutely congruent with the holistic way the founders of chiropractic described the subluxation, is inclusive of many of the subluxation models that currently exist and the practice models that address them, and offers new paths of inquiry for advancing our knowledge base as a profession.

The Adjustment

“Grooming describes a behavior concerned with the primary biological function of caring of the body surface. Similar behaviors are ‘‘scratching’’, ‘‘preening’’, ‘‘rubbing against objects’’ and ‘‘dust, sand, mud and sun bathing’’ and by spreading saliva on the fur in a hot environment. These behaviors may be directed at the body of the subject (autogrooming) and also at that of conspecifics (social grooming). Allo- and social grooming find their origin in the interiorization and repetition of the infant – mother relationship. Because grooming mainly occurs after various activities and stressors, it seems to be related to a state of relaxation and dearousal. What is of relevance for the present report is that a behavior directed to the outer surface of the body is accompanied by a reduced attention towards the environment and is accompanied by a shift in the stream of information reaching the biological system, a shift from the information coming from the environment (exteroceptive information) to the information coming from within the organism (proprioceptive information).” Recordati17

While chiropractors have known for over a century that the chiropractic adjustment is a valuable tool for restoring and enhancing a state of health and well being, the exact mechanism of how it works have been elusive. There has been a shift in the chiropractic research paradigm over the years to look at improvement in CNS function with the adjustment as the primary factor in the effectiveness of the adjustment. This has largely replaced the past paradigm of looking at the restoration of efferent information flow through reducing impingement on the PNS. While I cannot state the exact mechanism of the adjustments effectiveness, I would like to discuss the chiropractic adjustment relative to this ecologically driven chiropractic perspective.

From an evolutionary perspective, the healing arts are very likely an extension of primate social grooming behavior. This includes all branches of the healing arts tree through their development, from shamanism, to herbalism, to the current day, inclusive of chiropractic. Social grooming behavior activates the social division of the vagus nerve by directing the central nerve system towards an interoceptive focus in the presence of safety. This cues the nervous system to direct energy towards the restoration or enhancement of internal order.The development of a myelinated division of the vagus nerve intimately related with information and emotional communication that shifts our energy allocation towards internal housekeeping processes should indicate just how vital the development of social healing arts are to individual and group success in the near term. Their may even be a long term benefit to the evolution of the species from advancing its grooming behaviors in a way that optimizes the tone of the most evolutionary advanced division of its nervous system.26

The chiropractic adjustment may be one of the most advanced applications to evolve from primate social grooming behavior. Evidence-based Design has recently begun to transform the medical environment into something more hospitable with good results. Chiropractic environments have historically been designed to be pleasant rather than sterile. While chiropractic practice is not uniform in its culture, it is common place for chiropractors to see their role as cooperative rather than authoritarian in the doctor patient relationship.27 This mirrors the relationship between healer and patient in older healing traditions such as those of the North American First Nations.28 The chiropractic adjustment often involves a significant amount of doctor patient physical contact in an environment where trust and rapport must be established for the adjustment to be delivered comfortable and efficaciously.

While it may be tempting to attribute the beneficial outcomes of the chiropractic adjustment to the placebo effect in light of these observations, bear in mind that the chiropractic adjustment is directly addressing both the exteroceptively dominant state and its dysfunctional sequelae through the restoration of spinal function. The fixated vertebrae, distortion in spinal curvatures, alterations in neuromusculoskeletal tone, and dysfunctional biomechanics resulting from the exteroceptive dominant state described above, are all addressed directly by various chiropractic methods in an environment conducive to activation of the social division of the vagus nerve. The spine is used as a tool to access and influence the central nervous system through proprioceptive stimuli, an interoceptive phenomenon.29,30,31 By addressing the sequelae of the exteroceptive dominant focus in a manner and environment that fosters both social vagus activation and directly increases interoceptive stimuli and the focus upon it, a powerful intervention for spinal and general overall health and function is created.

A key feature of social grooming is that it’s effectiveness is dose dependent.17 Repetition of activities that reinforce parasympathetic activity seems to be an effective strategy for enhancing parasympathetic tone, as has been observed in yoga trainees32,33 and chiropractic patients.34 Apes who receive the most social grooming have the highest health status within their communities. They groom to establish relationships, create alliances, amongst other reasons. The amount of grooming received tends to correlate to social status. The loss of social status and the corresponding decrease in grooming frequency will decrease health status.35 Humans require a certain level of social stimuli for proper neurodevelopment as evidenced by the negative neurodevelopment outcomes of institutionally neglected Romanian orphans after the fall of Ceausescu.36

Chiropractic has been utilized both as a treatment for conditions and as a regular part of a healthy lifestyle for the promotion of enhanced well being. The social grooming aspect of the chiropractic adjustment may be what is conferring the ability to restore and enhance neural tone and build resilience in chiropractic patients through the restoration of an interoceptive CNS focus as a regular lifestyle habit.

Public Health Implications

The Question of Free Will

The question of whether or not humans have a conscious free will that enables them to exercise sovereignty over the trajectory of their lives has been topic of debate within the neuroscience community for decades. While experiments consistently show something called a readiness potential that will lead to a physical action if not inhibited, precedes the conscious perception of having made a choice, the significance of that finding is a topic of debate. The materialist perspective is that the readiness potential agrees with the idea that a causal chain leads to our actions and the perception of having sovereignty over our actions as a conscious being is an illusion generated by the brain after the fact. Others interpret it as a correlated phenomena that doesn’t necessarily negate the ability to express free will. One perspective is that, like other biological phenomenon, human actions are more probabilistic than deterministic, and the individual has the ability to influence current and future behavior through conscious higher level brain centers that integrate with the activity of subconscious lower brain centers.

On this side there has been proposed a sort of free will capacity index comprised of a repertoire of higher level cognitive skills related to control of behavior, contextualization and forward thinking/planning, rational capacity, and problem solving. When an individual ranks highly on the function of higher level cognitive functions they have a higher capacity to influence their behavior by choice. I describe this state of high free will capacity as sovereignty of mind, the ability of the individual to maintain self determination in their actions by engaging the world through higher level cognitive capacities located primarily in the prefrontal cortex.The intention behind the development of this free will capacity index was to introduce an objective measure of an individuals level of responsibility for their actions that can be applied by the justice system.2,3,4,37,38,39

The significance of this knowledge for implementing health care and public health policy should be readily apparent. If free will is limited to the ability of higher level cognitive functions to influence subconsciously driven behaviors that emerge probabilistically from a chain of external events interacting with conditioning from prior experience and genetics, then orienting health care delivery and public health policy around the idea that humans are free actors that will act in their rational self interest is likely to be minimally productive at best. Integrating the knowledge that behavior is probabilistic and influenced by a multitude of factors with rational choice much lower on the decision making hierarchy for a great number of individuals, may very well produce far better outcomes. Though would also generate its own new ethical challenges.

Sovereignty of Mind

A challenge to our sovereignty of mind is the inhibitory impact of even mild stress on the prefrontal cortex.

“When things are going well, the prefrontal cortex acts as a control center that keeps our baser emotions and impulses in check. The new research demonstrates that acute, uncontrollable stress sets off a series of chemical events that weaken the influence of the prefrontal cortex while strengthening the dominance of older parts of the brain. In essence, it transfers high-level control over thought and emotion from the prefrontal cortex to the hypothalamus and other earlier evolved structures.“ Amy Arnsten, Carolyn M. Mazure, and Rajita Sinha40

These effects are largely emerging from the influence of arousal chemicals such as norepinephrine, cortisol, and dopamine which decrease network connectivity in the prefrontal cortex and the ability to regulate behavior. Dopamine arrives at a series of deep-brain structures, collectively called the basal ganglia, that regulate cravings and habitual emotional and motor responses.41 Under chronic stress conditions the physical architecture of the brain itself is altered, with a decrease in the number of dendrites in the prefrontal cortex and an increase in those of the amygdala. The changes are reversible if the initiating stressor disappears and was not extreme in nature.40,41

This is very reminiscent of the discussion on the exteroceptively dominant state earlier in this paper. In the presence of a significant exteroceptive demand resources are shifted away from metabolically expensive domains such as proprioception and the prefrontal cortex. The musculoskeletal correlate for decreased prefrontal cortex function, is the shift to more gross, primitive, movement strategies governed by the systemic global muscle system and inhibition of the systemic local muscle system. Just as there are acute functional and chronic structural alteration in the central nervous system in response to stress, there are acute functional and chronic structural alterations in the musculoskeletal system.

This collective body/mind alteration in function and potentially structure that occurs as a result of an exteroceptively dominant focus is what I call the subluxated state. The body may shift away from this state of being on its own accord if it has the degree of resources and resilience necessary to do so, but may also require the assistance of some form of social grooming related intervention. The chiropractic adjustment is one of these interventions and may be the most effective intervention in an undetermined percentage of cases.

Sovereignty of Mind Through the Chiropractic Adjustment

Chiropractic adjustments are able to restore an interoceptively dominant state where access to higher level neural and cognitive strategies is increased, which is evidence by studies on chiropractic and heart rate variability, proprioception, sEMG, fMRI, stress hormone levels, and prefrontal cortex function, which all have relationships to the parasympathetic nervous system and interoception.29,30,31,34,42,43,44 As such, the chiropractic adjustment should also be improving mental and emotional well being and lead to better lifestyle choices. The spontaneous adoption of healthier lifestyle choices while under chiropractic care was reported in a retrospective case assessment of subluxation based chiropractic care of 2596 patients in 156 chiropractic offices.45 The years 1922 and 1956 saw the founding of two chiropractic sanitariums in Davenport Iowa. Judge A. W. Ponath of South Dakota noted significantly higher rates of “cure and release” at Forest Park Chiropractic Sanitarium than the South Dakota state mental hospital. There was a continued interest in chiropractic care and mental health from those years until the 1980’s, making psychological well being a focus of chiropractic for four decades.46

I am proposing that this observed effectiveness with mental and emotional dysregulation is, at least in part, due to the reduction of the exteroceptively dominant subluxated state. As the higher brain centers that have a descending influence on behavior, and emotions, including pain, are more recently developed from an evolutionary perspective, any intervention that activates or strengthens the activity of these centers should be able to help shift the individual out of that state. As the chiropractic profession was founded on restoration of the tone of the human neuroskeleton, it may very well be the intervention of best choice for this task.

Quantification – Thermodynamic Health Measures

As the evolutionary purpose for the development of nerve systems in general was likely the thermodnamically optimized regulation of metabolism in response to external energy flows and demands,15 these observations in regard to the sublimated state should also have observable impact on energy metabolism that could be measured to ascertain thermodynamic functional status. This has been done effectively in the science of ecology, and there are already measurements being utilized in chiropractic practice that function in a similar manner.

Ecosystem Health Measures

The dissipation of energy gradients creates an evolutionary drive to enhance the organization of these open and living systems in ways that increase their capacity to transform the energy of the sun and sea vents into higher entropy forms. life requires a constant flow of tremendous amounts of energy in order to maintain itself. The interactions between one living thing and several others create the potential for entire living systems to organize into interdependent webs with capacities to transform greater quantities of energy than a single organism. We see the development of trophic levels in ecosystems, of complex food webs, all optimized to capture and transform solar energy into heat. Stated briefly, living systems transform solar energy into other forms of energy with higher entropy, and this allows them to exist, reproduce, and drives them to evolve in ways that do so more effectively.8,9,10,11,14,15,16

Without ecosystems, and the terrestrial environments and atmospheres associated with them, solar energy spends very little time on Planet Earth. In a barren desert, solar energy strikes the sand and the majority is quickly reflected back into the atmosphere. Only a small amount is absorbed and transformed into infrared radiation by the heating and cooling of individual sand grains on the desert surface. In a tropical rainforest much of that solar energy is trapped by plant life and used for evapotranspiration and photosynthesis. The areas of Planet Earth that receive the most sun also tend to have the greatest abundance and diversity of life. Where the greatest energy gradients are present, the greatest concentrations of thermodynamically dissipative systems, i.e. living things, will be found as well.10,14

This creates a testable hypothesis. To quote Eric Schneider, marine geologist and ecological thermodynamicist, and James Kay, ecological systems engineer.

“As ecosystems develop or mature they should increase in their total dissipation, and should develop more complex structures with greater diversity and more hierarchical levels to abet energy degradation.”10

This can be observed in the process of ecological succession. This process of succession results in systems with the following.

* More energy capture
* More energy flow activity within the system
* More cycling of energy and material
* Higher average trophic structure
* Higher respiration and transpiration
* Larger ecosystem biomass
More types of organisms, greater diversity

As ecosystems experience stress, they will often transition to a lower level of thermodynamic transformational capacity. They begin to appear similar to earlier stages in their successional evolution. They shift closer to thermodynamic equilibrium, AKA death. And this is quantifiable in the real world. When examining two aquatic tidal marshes adjacent to a power generating facility on the Crystal River in Florida, Kay and Schneider were able to measure the difference in energy flow capacity of a healthy marsh ecosystem, and a marsh stressed by hot water effluent from the nuclear facility that increases the water temperature by 6 degrees Celsius. Total energy flow through the stressed ecosystem dropped by 21%. Biomass dropped by 35%. There was a 51% decrease in the total number of cycles in the stressed ecosystems food web. Essentially, the stressed ecosystem shrank in its biomass and ability to transform energy. It became a “leaky” system, less able to capture and transform the incoming energy inputs.10

Another method of assessing this capacity to thermodynamically transform solar energy gradients is by measuring the difference in black body temperature between the captured solar energy and energy re-radiated by the ecosystem. Given the same input of solar energy, we should be able to predict the most mature ecosystem would have the coldest black body temperature. When comparing a quarry, a clearcut, a Douglas Fir plantation, a natural forest, and a 400 year old Douglas Fir forest, the coldest site was the mature forest and the warmest was the clear cut. When comparing the amount of solar energy degraded by the ecosystems, the quarry degraded 62% of the net incoming solar radiation. The 400 year old forest degraded 90% of the incoming solar radiation.10

Human Correlates

The history of thermodynamic measures in chiropractic practice begins practically concurrently with the development of the profession. The founder of chiropractic, DD Palmer, at least as early as 1903, formally described the importance of nerve function in thermoregulation and was assessing temperature differentials within the body for therapeutic purposes even before the development of chiropractic. In 1924 his son BJ Palmer introduced a thermographic pattern reading device known as the neurocalometer that was designed to objectively measure asymmetrical thermal patterns along the spine. Over a dozen other instruments with a similar purpose would be subsequently developed and used widely in chiropractic practice. This legacy is carried forward to the current day and several thermodynamic measures have been employed in chiropractic practice and research.47

Surface Electromyography is one measure currently in use. By measuring the amplitude of electrical activity along both sides of the spine and comparing against normative data for healthy spines, valuable objective data on the amount of energy being mobilized to combat gravity and other kinematic forces can be obtained.48,49 This information can be used in a number of ways, but is essentially a measure of thermodynamic efficiency. Thermography is employed in similar fashion with radiant heat is being measured rather than direct muscle activity. Both measurements are often used for pattern reading, which is the analysis of multiple readings across a period of several days to weeks. It is considered ideal for subsequent readings to show a variance from the original readings, which indicates the body is in a neurologically dynamic and adaptable state. Similar readings over time indicate a decreased ability to adapt.50

Heart Rate Variability (HRV) is another thermodynamic measure regularly employed in chiropractic practice. While we do not have a complete picture on what HRV measurements indicate, we do know that HRV measurements correlate with health status. As HRV is a composite measure of a number of factors that are not completely understood, it is impossible at the moment to gain a complete picture of what the shifts in HRV that have been observed with chiropractic adjustments indicate, though the results have been generally interpreted as favorable.34,51


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