Having begun the online portion of my acupuncture course, I am beginning to get into the work of identifying, remembering, and locating the main acupuncture channels and points that are used for clinical treatment in several varieties of acupuncture. This section of the course touches on a key point I have discussed previously about acupuncture, namely do the points and channels acupuncturists use for needling exist in any verifiable sense?
Do Acupuncture Cannels and Points Exist?
TCM and other folkloric acupuncture styles utilize particular locations for needling based on maps or descriptions from historical sources, sometimes ancient but often more recent that you might think. Veterinary acupuncturists, in particular, utilize systems that are quite modern inventions since traditionally Chinese medicine did not involve fine needling as a therapy for animals. The rationales given for the locations of these points and channels are unscientific and unverifiable talk of energy forces, and historical research suggests they were dictated as much by astrological, philosophical, and religious principles as any observation of clinical effects in patients. As I have already pointed out, I don’t see any value in taking such unscientific approaches seriously.
Medical acupuncturists in more conventional, science-based practice, however, tend to try to rationalize the use of acupuncture maps adapted from traditional or folkloric sources by identifying measurable anatomic or functional features to the points chosen. They frequently claim that such points and channels can be consistently associated with nerves, locations where nerves divide or emerge from channels in bones (foramina), blood vessels and their associated innervation, tendons and ligaments, and the connective tissue planes that separate muscles and other structures (fascia). They may also claim that there are special features of the tissue in the region of acupuncture points identifiable with biopsy, with equipment testing electrical conductivity, or by other means. Some also claim that acupuncture points often correspond to “trigger points,” areas of pain or sensitivity which are themselves somewhat uncertain in definition. Stimulation of these sorts of structures could plausibly have physiological and even clinically beneficial effects since there are functionally important means of communication between different parts of the nervous system, and between nerves and other anatomic structures and organs.
The question then becomes what is the evidence for such claims? Are acupuncture channels and points just metaphoric ways of describing nerves and other anatomic structures that we understand in ways folk acupuncturists in history could not have? This is not an easy question to answer. A nice review of this subject by Dr. David Ramey points out that:
Research on the nature of acupuncture points and meridians is often difficult to evaluate because of the diverse nature of the claims made, incomplete data provided in published studies and the variety of parameters involved in the assessment of these claims. Many of the studies purporting to have identified acupuncture points or meridians come from China; the role of publication bias in Chinese literature needs to be considered in light of the fact that no trial published in China from 1966 through 1995 found a test treatment to be ineffective.
There is no question that if you take a particular channel or set of points from any acupuncture map and look at the anatomy underlying it, you can find all sorts of structures that could possibly respond to needling in potentially beneficial ways. But there are a number of problems with this strategy.
Acupuncture channels and points are quite vague and inconsistent between schools of acupuncture and individual acupuncturists. Some even in the acupuncture community have denied that the location of needling matters at all. And even among well-trained and experienced traditional acupuncturists, the identification of particular points can vary considerably. One study found the following:
This study took the approach of testing whether properly trained and experienced acupuncturists could consistently identify commonly used acupuncture points on a single patient. Twenty-three common points were selected and identified by the 71 test subjects. The area within which specific points were identified by 95% of the acupuncturists ranged from 2.7cm in diameter to 41.4cm in diameter. Because of the variability with which experienced acupuncturists identified common acupuncture points, the authors concluded that to stimulate fake points as a placebo control for a clinical trial, it would be best to stimulate the skin at least 6cm away from the spot identified as the real point on the face or hands and at least 12cm away from a proposed real spot anywhere else on the body.
Given the vague nature of points and channels, and the fact that structures which might respond to needling are densely packed in nearly every part of the body, it is inevitable that any map at all is likely to overlie some structure that could be claimed to be the intended target of stimulation. It would be like dropping a large net on a sidewalk in Manhattan and then claiming that the location chosen was exactly the right one because some people were caught in the net. The same outcome would have happened wherever you dropped the net. Similarly, much clinical research shows that the apparent effects of acupuncture seem to be the same regardless of the location chosen for needling. Indeed, even some prominent acupuncturists have claimed that the location for needling is irrelevant.
The question of how folkloric practitioners could have come up with maps of anatomic structures that had not yet been discovered is also a bit problematic. Since it is clear that traditional systems for locating acupuncture points relied heavily of spiritual beliefs, astrology, and the like, it seems unlikely that they would be in any sense anatomically accurate. Some argue that by trial and error, acupuncturists might have found effective needling locations and then rationalized these with pre-scientific theories. This too seems unlikely, however, given how ineffective trial and error is in finding effective medical treatments, and also given the fact that early acupuncture was often a system for bloodletting, and the anatomic structures of interest would most likely have been blood vessels.
The section of the course I am currently working on requires learning the names and locations of acupuncture channels and points. While the rationale given for the use of these points is based on the physiologic and anatomic arguments I have outlined, the nomenclature used is still that of traditional folkloric acupuncture. The WHO accepts an alphanumeric nomenclature and Chinese names for acupuncture points based on the traditional system, and these are used in this course. This system requires classification of channels as Yin or Yang based on designation of associated organs in order to help keep track of the point numbering system, even though the concepts of Yin and Yang are specifically rejected in the curriculum.
The reasoning here is that the use of this nomenclature is widespread and entrenched and facilitates communication between practitioners of different schools, so it must be tolerated. However, the use of these terms does not imply that the underlying metaphysics has anything to do with the function of the channels and points, which are intended to be defined and understood in terms of anatomic structures and physiological functions.
This may be innocuous, like referring to sunrise and sunset even though we now know that is an erroneous characterization of celestial mechanics, or referring to the days of the week and months of the year by the names of gods. Still, it seems unfortunate since it lends some sense of legitimacy to those who still actively use the system as if the metaphors were actual descriptions of reality. I would think that a serious commitment to a scientific approach to acupuncture might ultimately require renaming any maps of locations for needling used in terms of the actual anatomic structures or physiological functions they are supposedly associated with.
While it makes sense that needles nerves, tendons, and other such structures could have beneficial effects, the evidence that traditional acupuncture maps have a meaningful or predictable relationship to these structures is weak. The associations claimed between acupuncture channels and points and identifiable anatomic structures seem more likely to be rationalizations after the fact for locations originally chosen without any actual understanding of or relationship to functional anatomy and retained as historical holdovers.
If the proposed effects of acupuncture really do relate to stimulation of nerves, myofascial planes, etc., it would make more sense to argue that the locations chosen for needling should be selected on the basis of the location of such structures and research showing functional responses to needle stimulation of them. There would then be no need for terms like Bladder 2 and Governor Vessel 12. We could simply say we are needling the radial nerve or the trigeminal nerve, and we would be more accurate and less associated with folkloric acupuncture practices.