Why Are Acupuncture Points Located Where They Are?
Patients often ask, “Why are you needling my hand when the problem is in my sinuses, or needling my foot to treat tooth pain? Why are the points always somewhere other than where my problem is?” The quick answer is that these are the most effective points for that condition. A slightly longer explanation might include that acupuncturists have been refining and passing on this knowledge for over two thousand years.
None of these responses answer the question of why the points are where they are. Sure, you can say, “That’s where the meridian is”, but then why is the meridian there and not somewhere else? Every acupuncturist knows that the classic points are by no means all of the possible points, and that just because the knowledge was codified over two thousand years ago doesn’t mean that no more knowledge is possible.
The Nei Jing is the foundational book of Chinese Medicine. Scholars generally agree that the written work is dated to somewhere in the late Warring States Period (475 – 221 BC) and the Han dynasty BCE 220 to CE). The Nei Jing consists of of two parts, the Suwen and the Ling Shu. The format of the Nei Jing is a conversation between the semi mythical Yellow Emperor, Huang Di (黃帝) and his court physician, Chi Bo. Though there were no surviving written records from the time of the Yellow Emperor, oral tradition suggests that he lived approximately 2,600 years ago. Due to the Chinese cultural reverence for ancestors and their high regard for the Nei Jing, later authors and innovators in Chinese medicine generally describe their discoveries as commentary on the Nei Jing, rather than taking a fresh look at the underlying theories.
Not being content with re-interpreting the classics, I (with the help of my son Michael) have developed a theory that integrates classical acupuncture knowledge with modern science, particularly embryology. This has helped us in our clinical practice to find dozens of novel points. The purpose of this article is to outline that theory so that you too, can predict and discover additional effective acupuncture points.
To explain our theory requires a review of embryology. Sperm and ovum meet. The two cell nuclei combine, forming the basis of a new body with genetic material from each parent. This combined cell is called a zygote. The zygote then divides in two. The two resulting cells divide in two and so it goes as two becomes four becomes sixteen, becomes thirty-two. At this point, the 32 cells are still the same size as the original zygote. The zygote takes on the shape of a hollow ball and attaches to the uterine wall.
During the third week after fertilization, the continually dividing cells begin to organize themselves into three layers. These are known as the Ectoderm (which will become the skin, hair, nails, brain, spinal cord and peripheral nervous system), the Mesoderm (which will become muscle, bone, connective tissue, kidney, gonads and circulatory system) and the Endoderm (which will become the digestive tract, liver, pancreas, bladder and lung). At around this same time (day 16), the beginnings of the brain and spinal cord appear as a “neural streak”. This is the first visible structure in the developing embryo.
This is important to our theory. The brain and spinal cord are already forming and developing an “image” of the body while the body is just three interconnected layers of cells that link future internal organs with cells that will become muscles and skin. Think about that for a moment. Acupuncture points in skin and muscle stimulate effects in internal organs.
Then think about this; the nervous system is creating an image of the body while it is still a ball. Right and left, top and bottom are still undifferentiated. It is the neural streak that becomes the dividing line between the right and left sides of the body and also defines top from bottom. In other words, the neural streak is present at the beginning and likely is involved in directing the further development of the embryo.
The neural streak forms a thick, flat plate of cells called the neural plate, which then bends to form a tube the length of the body. This is called the neural tube. It will become the brain and spinal cord. The outer layer of the neural tube forms the neural crest, which will become the sympathetic and parasympathetic nervous systems.
At the same time, the mesoderm is forming into multi-layered tube. The paraxial layer of the mesoderm will give rise to muscle, cartilage, bone and dermis. The intermediate mesoderm will become kidneys, gonads, adrenal glands and the rest of the urogenital system. The lateral plate mesoderm will become the heart, blood vessels, the body wall and the muscles in our internal organs.
Concurrently, the endoderm is also rolling into a tube. That tube will become the digestive tract. The upper part of this tube forms pouches that will become the esophagus, stomach, part of the duodenum and a bud that will develop into the lungs. The midsection develops into the rest of the duodenum, small intestine, ascending and transverse colon. The final section becomes the remainder of the transverse colon, descending and sigmoid colon, and the rectum.
All the time that these cell layers are forming into tubes, budding and developing into muscles, organs and bones, the early nervous system is wiring everything together. We hypothesize that the effectiveness of distal acupuncture points is a remnant in the mature brain’s memory of the original developmental plan in the embryo.
What does this have to do with meridians?
In Chinese medicine, the kidneys, adrenals and gonads are all lumped together as “Kidney”. Anatomically and functionally they are quite different structures but embryologically, they derive from the same tissue. Presumably, the linear distribution of associated muscle and skin that we needle to affect those organs arose from adjacent tissue during the process of differentiation. In other words, the “meridians” of acupuncture are tissues that are neurologically related because of their proximity to each other during embryological development.
Similarly, the lung and large intestine are considered to be paired organs in Chinese Medicine. There is no obvious special relationship between those two organs in Western Medicine. It’s possible though, that they do share some common signaling pathways because they both derive from the endoderm. No one knows at this time what neural connections are present in the developing zygote and embryo, but it is clear that the nervous system is already present as the organs and other structures are forming.
The unique contribution of Chinese Medicine is its recognition that the body is organized in lines of associated tissues that run from head to toe. For example, the Yang Ming meridian runs from the eye to the second toe. Points along that pathway are used to treat stomach conditions, shoulder bursitis, eye or jaw pain, etc. What do all these areas have in common? I suspect it is that they arise from common or adjacent tissues in the developing embryo.
It’s very confusing for Westerners to try and wrap our heads around a pathway that relates so many disparate tissues. It’s made worse by the unfortunate naming of these pathways by Jesuit missionaries in the 1700’s. They named the pathways after organs, as in the case above, the stomach. That sort of reductionistic thinking makes it hard to explain to patients because needling a stomach or liver or kidney point doesn’t mean that there is anything wrong with the named organ.
Worse, the Jesuits understanding of organs was still rooted in Hippocratic medicine. So for example, they would conceive of blood rushing to the head causing anger, headache or even stroke due to an over active liver. Many discredited ideas from Hippocratic medicine are hung around the neck of Chinese medicine, making it seem all the more outdated to Western science.
It gets worse…
The widespread belief that acupuncture is a pseudo-science was compounded by Georges Soulie, a translator in China in 1910, who was forced out of China and sent back to France during the Boxer Rebellion in 1911. Unemployed in France, Soulie began writing books about Chinese culture. While it is not known if he ever actually witnessed acupuncture being performed, in 1939 (28 years after leaving China) he wrote a book about acupuncture that described meridians as invisible pathways of vital energy circulating in the body. This idea was very popular to people in the West who were looking for a “vitalist” explanation of health that connected the individual to cosmic, spiritual forces. In other words, it presented a pseudo scientific explanation that appealed to people looking for spiritual solace.
Contrast this with the Chinese, who were dissecting nerves and blood vessels while my ancestors were throwing spears and painting their faces blue. Soulie did all of us a disservice. His translation of “Chi” as vital force for instance, misses the mark. To the Chinese, “chi” means “air”, “weather” and “metabolism” as in aerobic metabolism (which is dependent on air). Yes, metabolism means energy in the sense of electromagnetic forces involved in ATP production or other chemical reactions in the body but it does not mean mysterious, cosmic energy or life force, independent of biological processes.
The cosmic aspect of Chi arose because Chinese used weather metaphors to describe moods and bodily conditions, i.e., “her face clouded over with sadness”, or, “she had a sunny disposition”. That does not mean that various types of cosmic chi are creating a disturbance in our minds and bodies. The Chinese also related weather to physical conditions as in “he caught a cold” or, “had heat exhaustion” or, “his arthritis feels worse in cold, damp weather”. To read or hear acupuncturists talk about “cold”, “damp” or “heat”, you get the impression that these actual environmental factors are abstract, metaphysical archetypes with a life of their own. But I digress….
Getting back to embryology, our bodies are organized as bilaterally symmetrical, segmented tubes, divided by a spine. This is a basic organizational principle going back to flatworms, over 500 million years ago. It makes sense that we can needle the right elbow to treat the left elbow and as noted above, there is also a linear organization of related tissues following the axis of those tubes in the developing embryo. Here comes a trickier thought; The segments are also related to similar structures further up or down the tube. How does that work?
Think of this. Your thumb looks and functions a lot like your big toe. Your elbow divides your upper limb the way your knee divides your lower limb. Your shoulder and hip are the attachments of your upper and lower limbs to your trunk. We are not only symmetrical from right to left. We are symmetrical from top to bottom. Imagine your body folded up in a ball, so your head and hands were touching your feet. Your wrists would overlap your ankles. Your elbows would be next to knees, etc.
If you think of it this way, many acupuncture point locations are explained. Better yet, you can predict the location of acupuncture points just by knowing anatomy.
How I arrived at this theory
I had been looking for more effective distal points for several years. I knew a handful of distal points that could work what can only be described as miracles; Yao Tang Xue for sciatica. St 38 for shoulder bursitis. SJ 5 for acute sore throat… Instantaneous, complete relief. Nothing in Western medicine could compete with these results and nothing in Western medicine could explain them. I reasoned if there were a few of these points, there must be hundreds.
I attended a class with Dr. Richard Tan. His work and that of Dr. Tung before him pointed to the kind of instantaneous success from distal points that I was seeking. I found however, that their rationale for point selection didn’t fit for me in the hurry of clinical practice. Should I select points based on the Mother-Son relationship, Midday-Midnight, 5-Elements, mirror image, reverse mirror image, etc. There were too many choices. Also, There were so many overlapping rationales for so many points it seemed that one could justify just about any point with one rule or another. In short, I felt it lacked specificity and was cumbersome for me to use. (I wish to be clear that this is not an indictment of an excellent system of point selection. It just didn’t work for me).
I did feel that mirroring was a correct concept. I had been experimenting with mirroring with some success prior to taking that class. I also felt that the points had to derive from embryological development. I was guided to this thought in part by a book I had read in the early 1970’s by Felix Mann, MD. i
Well as they say, necessity is the mother of invention. One busy Summer day, all five treatment tables were loaded with patients and I had two more in the waiting room. One room opened up and I brought in the next patient. She was a middle aged woman with right buttock pain. She wore a spaghetti strap top with a girdle under her skirt. I had no time to wait for her to change into a gown to get access to her hip. I noticed that her right foot was turning out as she walked into the room. I asked to to turn her right foot inward towards the left foot. That immediately caused a sharp increase in her right buttock pain. As I suspected, her right piriformis muscle was tight and painful. How to release it quickly? I thought for just a moment and realized that the piriformis muscle externally rotates the lower limb. What muscle externally rotates the upper limb? Aha! The infraspinatus muscle. I quickly needled the most tender point in the belly of that muscle (SI.11) and asked her to rotate her right foot medially and laterally. Within seconds, the pain was gone! I told her to keep walking and testing her leg to be sure the buttock pain was gone until I came back.
I quickly went to the next woman. She too was wearing an outfit that exposed her shoulders and she too had a pain in her hip. In her case, she pointed to the side of her hip. I palpated and found tenderness at the greater trochanteric bursa. Again visualizing the anatomy, I thought, “What’s the bursa that reduces friction when abducting the shoulder which is similar to the bursa that eases abduction for the hip?” I needled a non-classic point in the sub-deltoid bursa and her pain immediately disappeared! Success! I removed the needle from the first patient and was soon able to get back on schedule.
Principles of Point Selection
What I came to was a set of principles for selecting distal points, namely that I look for;
1. Homologous structures.
2. Of the same tissue type.
3. With a similar function.
I think numbers 2 and 3 are self explanatory but just to be sure this is clear; If the problem is in a muscle, needle a distal muscle. If the problem is in a bursa, needle a distal bursa (as above). These are the same tissue type. Similar functions are illustrated in the examples above, i.e., muscles that externally rotate the limbs relative to the trunk and bursa that ease abduction of the upper and lower limbs. The first principle however, needs a little clarification.
I use the term homologous which the dictionary defines as “having the same relation, relative position, or structure” to describe anatomically similar structures. Going back to what I was saying about embryology; your hand is like your foot, your knee is like to your elbow, your hip is like your shoulder. Obviously, your thumb is similar to your big toe, but what part of the elbow is paired with what part of your knee. Think of this. Your radius aligns with your thumb and your tibia is aligned with your big toe. If you lay your palm down over your foot, the relationship is clear. You may notice that in this position, your knee flexes backward while your elbows flex laterally. Think of the hollow of the elbow (antecubital fossa) and the hollow the knee (popliteal fossa) as mirroring one another. This makes even more sense if you think of how these joints function in a quadruped. That means if you were treating a Baker’s Cyst (popliteal bursitis), you would needle the center of the antecubital fossa (LU5) in the bursa of the elbow. If you were treating a medial meniscus sprain, you would needle LI12. The lateral meniscus would be treated near HT3. You might treat the anterior tibialis muscle by treating LI10, or the quadracep femoris by needling the tricep (near LI13). Get the idea?
A less obvious relationship is between the scapula and the pelvic (innominate) bones. Following this logic, you can needle SJ 15 to treat the quadratus lumborum or HT 1 to treat the psoas. I will detail some of these relationships below.
I should mention a few other principles at this point;
1. Distal points are most effective for reducing pain and inflammation while local points are best for releasing muscle tension and attracting an immune response to the area. The reason that local points are more effective for releasing muscle tension and attracting an immune response is because the release of Substance P in the cells that are pierced causes local muscle relaxation and immune cell chemotaxis (the attraction of immune cells to the site of the injury). Distal points create a greater impression of injury in the brain, stimulating more endorphin and steroid release. Distal points may also create a greater neural blocking effect (Melzack-Wall Gate Theory).
2. For best effect, needle distal areas with a high density of pain fibers compared with the area of complaint. So for example, you’ll get a better result needling the shoulder for the hip and the elbow for the knee than the other way around. Hand to foot is the same either way. You will get some benefit needling a knee to help the elbow, but will likely need to treat local points in the elbow for best results.
3. Move the area of complaint while the distal points are inserted and painful. This increases the effectiveness of treatment and helps the patient get over their fear of moving the injured area. I used to ask patients to walk around when I needled Yao Tang Xue for sciatica. I have a large room in my office that has three treatment tables. I also have two private rooms. One morning, I had two patients in the large room. Both of them had sciatica from disc lesions. One was a dancer, the other a film producer. When I had them both walking around with needles in their hands, the dancer said, “Now that we can walk without pain, we should dance!” She then proceeded to teach all of us the samba. Since then (late 1990’s) I have been teaching the samba or encouraging other dance forms while the patient is retaining the needles. The psychological benefit of the patient shifting from thinking they may never walk again to dancing pain-free cannot be overstated. Similarly, the family members who assisted the patient as he or she limped in are delighted to see them dancing out under their own power.
4. This should be obvious, but the distal points must cause a deep ache (da qi) to be most effective. A deep ache is necessary because we are trying to trick the brain into thinking that a far worse injury has occurred. The greater the ache, the larger the area of representation in the brain and subsequent recruitment of healing resources.
In addition to the homologous joints, there are areas that form a homunculus and can treat the whole body. The best known homunculi are the ear, hand and foot, though there may well be others. We have noticed that needling distal to Yao Tang Xue in the grooves adjacent to the third metacarpal progressively treats spinal areas up through the lower lumbar, to thoracic to the cervical spine at Ba Xie (metacarpal phalangeal joint).
The exciting lesson to learn from all of this is that there is more to discover. As practicing acupuncturists, we can continue to add to the literature, rather simply try to better understand the lessons our acupuncture “ancestors” left for us. I hope this article inspires you to continue the search for better ways to serve our patients, rather than becoming the basis of a new dogma.
David Wells, D.C. L.Ac.
i Acupuncture: The Ancient Chinese Art of Healing and How it Works Scientifically by Felix Mann, MD.