Forms of stimulation to specific sites on the skin have been used for at least 3000 years. However, it is only in the last 25 years that comprehensive studies of acupuncture as an alternative therapy have been seriously undertaken in this country. The fact that meridian therapy has a beneficial effect on the control of disease processes seems evident today on the basis of empiric evidence and clinical studies.

Theoretical Concepts

Although it generally matters little to patients as to why they get well under a certain therapy, they do, however, expect that the doctor rendering that therapy has an acceptable explanation and understanding of the biologic mechanisms that are probably involved. That is, the patient has a natural tendency to believe that their doctor selects a particular procedure of treatment for their condition on the basis of his or her knowledge of the nature of their problem, and the knowledge of the underlying principles behind a particular method of therapy. Also, since the study and effective application of meridian therapy require some basic knowledge of its theoretical scientific basis, the need for this explanation is established.

In the case of meridian therapy, a number of theories have been advanced that generally fall under the headings of "Neural" or "Nonneural" concepts. These concepts attempt to explain the scientific basis for the biologic effects of meridian therapy in terms of our present understanding of human anatomy and physiology. Although scientific verification of the concept of "vital energy" as a physiologic probability and the "meridian" system as an anatomical fact have yet to be conclusive, verification for some of the effects of meridian therapy does exist on the basis of these concepts. [2]

The Nonneural Theories

One of the most commonly mentioned nonneural concepts attempts to explain the meridian system by proposing an elaborate conducting system of what is referred to as "Bong Han Ducts and Corpuscles." This theory, put forth by a North Korean physiologist and acupuncturist, Kim Bong Han, is a histologic description of elongated tubular cells lying deep in the skin. Han also thinks that a "unique" fluid circulates through these channels, which contains a high concentration of ribonucleic and other amino acids. Han believes that this fluid travels slowly through the meridians, completing a cycle each 24 hours. [3, 4]

Han’s theory, however impressive as it might be, has for all practical purposes been refuted by other investigators. Kellner has shown that some of this theory is based on artifacts occurring in preparation of the histologic slides, and other attempts at duplicating the work of Han reveal that he was probably describing the lymphatic channels of the body. [5, 6]

Various other theories have attempted to explain acupuncture and the existence of the meridians. [7] For example, magnetic fields, quantum mechanics, contraction waves of skeletal muscles, discharging of electrical potentials, and the release of histamine and epinephrine by stimulation of points have all been put forth as possible mechanisms. Others have likened the pinprick in the body to the electrical discharge of a condenser. At one time, Felix Mann proposed a theory based on the lateral line system in fish. These theories, along with others, have now been dismissed in favor of one of the neurologic explanations.

One of the most recent theories has been postulated by Koyo Takase in Japan who concluded that the so-called Qi energy circulating through a "meridian" in acupuncture therapy is actually extravascular sodium. [8] His studies involved the use of radioisotopes.

The Neural Theories

It is generally conceded that the mechanisms of many effects of acupuncture are similar to but not identical to those of the nervous system. There are many questions, however, that remain unanswered. [9]

When an acupuncture point is stimulated, it has been observed that the patient will often experience a change in seconds and this change frequently occurs at the opposite end and contralateral side of the body from the point stimulated. The exact mechanism of this action is not yet fully understood, although certain aspects appear to be based on established neurophysiologic concepts. This indicates that some type of nerve conduction occurs, as nerve fibers transmit impulses at an extremely rapid rate through their pathways. Such a rapid speed of conduction excludes the blood and lymphatic systems as possible mediators of this response.

      THE CUTANEOVISCERAL REFLEX

Acupuncture is founded on the premise that stimulation of the skin has an effect on distant internal organs and functional mechanisms of the body. Various experimental data tend to support the involvement of a cutaneovisceral reflex. [10–13]

Proof for the existence of such a reflex has strong scientific support. In a series of experiments, Kuntz and Hazelwood stimulated the skin on the back of rabbits and rats and noted changes in various parts of the gastrointestinal tract that were related to the dermatomal segment stimulated. [14–16] In Germany, Wernoe stimulated a small segment of the skin of fish and amphibians with silver nitrate and, after a delay of several months, demonstrated vasoconstriction of the part of the intestine dermatomally related. [17] After these experiments, he deduced that vasodilation was mediated by a spinal reflex and that vasoconstriction was mediated by a postganglionic sympathetic reflex.

Travell and Rinzler found that complete and prolonged relief resulted when trigger points on the front of the chests of patients with angina pectoris or acute myocardial infarction were infiltrated with procaine or cooled with ethyl chloride. [18] Thus, the cutaneovisceral reflex is of prime importance in acupuncture. It is strongly believed that, by its mediation, an acupuncture needle placed in the correct part of the skin is able to influence the related organ or diseased part of the body.

New hypotheses are being brought forth rapidly. For example, it has been established for years that the ear is a hologram of the body as a whole, and this is the basis of auriculotherapy. However, Dale has recently proposed an elaborate hypothesis that most any part of the body is a hologram of the body as a whole. [19]

      THE VISCEROCUTANEOUS REFLEX

Next, an explanation of how a visceral problem can relate to areas of the skin should be given. One method is by postulating the viscerocutaneous reflex. The importance of such a reflex rests in two primary areas: (1) diagnosis and (2) lowering the threshold of stimulation required in treatment with acupuncture. [20]

Various researchers have attempted to show that visceral problems may refer to the skin and give rise to trigger points, acupuncture points, and/or subluxations. [21–23] Diagnostically, certain superficial areas have long been known to relate to an underlying visceral condition such as pain at McBurney’s point in appendicitis, in the left arm in angina pectoris, and of the right shoulder in gallbladder disease. It is often noted clinically that a disease in an internal organ will produce pain, tenderness, hyperesthesia, or hypesthesia, etc, in some area of skin. The viscerocutaneous reflex is thought to be mediated by unknown pathways of the sympathetic chain. [24]

The Head-McKenzie Sensory Zone, as described by Judovich and Bates, shows how visceral pain can radiate to certain parts of the skin. A familiar example is cardiac ischemia with radiating pain to the left arm. [25, 26] In this context, Wernoe stimulated the rectum of a decapitated plaice electrically and found that the skin became pale. He also stimulated areas of the gastrointestinal tract of the eel and cod and noted that in each case the skin became lighter over an area of several dermatomal segments. [27] It can therefore be readily appreciated that a visceral problem can exhibit in a specific dermatomal segment via a viscerocutaneous reflex and that the stimulation of the skin can have a distinct effect on a related visceral area via a cutaneovisceral reflex.

Standard Methods of Stimulation

Acupuncture points are commonly stimulated by several methods:

1. Using 30-, 32-, or 34-gauge, 1/2 to 1-1/2-inch stainless steel needles that are carefully inserted at specific preselected sites for durations ranging from a few seconds to 20 minutes or more.
   

2. Using electrical stimulation with any modality designed for this purpose.
   

3. Using a specially designed blunt instrument (teishin).
   

4. Using finger or thumb pressure.
   

5. Using a helium neon or infrared laser (controversial).
   

6. Using tiny beads sometimes called acupatches or acu-aids.

Other methods of stimulation include use of moxa (a herb that is burned near or on the skin), sparks from a hand-held device, and microcurrent stimulators, to name a few.

When low-volt electric modalities are used in stimulating acupoints, it is generally believed that a frequency of approximately 5 pulses per second (pps) is ideal for maximal endorphin release. The intensity of current, using a small diameter electrode, should be as high as the patient can comfortably tolerate. Stimulating the most painful trigger point contralateral to the patient's pain (eg, elbow) while the patient moves the involved part has been found effective in rapidly alleviating musculoskeletal pain.

In summary, when acupuncture sites are stimulated by means of low-volt electric current, several factors should be kept in mind:

1. The exact site of the point or of its contralateral partner must be stimulated.
   

2. A small diameter electrode must be used.
   

3. The correct frequency must be selected.
   

4. The correct duration must be determined.

It should be noted that many of these factors are also important when other methods are used.


Site Location

Acupuncture points are usually tender to the touch and located in palpable depressions under the skin. Although most pertinent sites are usually tender, there are many situations where a lack of normal tenderness at a site may also be diagnostic.

As previously described, recent evidence suggests that acupuncture works by means of an extravascular transport mechanism. This means that the points will be located at a certain depth below the skin surface. Some research studies indicate that stimulation primarily affects the nervi vasorum (autonomic fibers congruent with the blood vessels), and this further lends credence to inserting the needle to a specific depth.


Locating Points

Of prime importance in meridian/trigger point therapy are the proper palpation and localization of the acupoint. But first, a specific definition of a meridian point should be attempted.

Felix Mann states that in all diseases, physical or mental, tender areas are present at certain points on the surface of the body — points that disappear when the illness is cured. He calls these sites acupuncture points. In Chinese literature, we find descriptions of over a thousand of these points. The more common 365 points are located on certain fixed lines or pathways called meridians. It is our opinion that an acupuncture point is, in many instances, identical to the trigger point described by Travell or the concepts described by Matsumoto and Hiyodo in their writings.

In locating important acupoints for treatment and meridian dysfunction, one technique involves systemic palpation (ie, of alarm points) of the body at predetermined sites. These points will be described later in this chapter.

      BACKGROUND

The palpating hands of the examiner contain sensitive nerve endings that are quite perceptive to changes in tissue tone, temperature, texture, surface humidity, etc. The fingertips are particularly well supplied with touch and pressure receptors, while the dorsal surface of the hand is especially endowed with heat receptors. For these reasons, both the fingertips and the back of the hand should be used during the evaluation procedure. As examiners gain experience in point location, they will find it increasingly easier to locate critical sites.

Acupoints will often be found that are spontaneously tender. For instance, a patient with appendicitis will point to McBurney’s point as being exquisitely painful. Individuals with headaches often relate a spontaneously tender area on the nuchal line of the occiput. In other cases, areas will be painful only when pressure is applied. Many of the points above the ankles and in the hand and wrist belong to this category. A third type of acupoint is not tender even when moderate pressure is applied. Many acupuncture points are of this type.

      PREPARATION

In searching for the acupuncture point, the patient must first be positioned in a comfortable position. The patient should be disrobed in such a fashion that the points are readily accessible to palpation. Care must be taken in all cases to preserve the modesty of the patient. As during the routine physical examination, it is generally best to have the patient undress and then robed in a gown that ties in the back. The waist band of the patient should be loosened for comfort and to afford free access to points of the lumbar, sacral, and lower abdominal areas.

Most examiners find it convenient to begin the examination with the patient seated on a low stool, and then transfer the patient to a comfortable cushioned table for examination in the prone and supine positions. Prior to searching for acupuncture points, the doctor should remove any jewelry that might scratch or irritate a patient. Personal hygiene, as always, is of utmost importance. The examiner’s hands should be thoroughly washed before and after each examination.


      TYPES AND CHARACTERISTICS OF ACUPUNCTURE POINTS

Several types of acupuncture points or lesions might be discovered:

1. Fibrositic nodules.   Most commonly, the fibrositic nodule will be the point located. This area feels like a small node or mass of tissue several millimeters in diameter. It will be tender to pressure and often spontaneously painful. It is similar to the fibrositic rheumatoid nodules often located at the back of the neck, in the shoulders, or in the lumbar area.
   

2. Indurated areas.   In many instances, a hard (indurated) area will be found. Instead of a nodule, the palpator might feel a localized area of tense muscle fibers in a muscle.
   

3. Atrophic areas.   In other cases, the acupuncture point might be characterized as a localized swollen and discolored area or an atrophied area of tissue.
   

      ELECTRIC ANALYSIS

The examiner might be unable to locate acupuncture points by palpation. In these cases, it may be of value to make use of one of the many electric devices available for their detection. These instruments measure skin resistance to an electric current, showing areas where the resistance is altered. Once a point is localized, whether manually or with an electric device, it should be carefully marked with a skin pencil or felt-tipped pen and then charted in the patient’s records so that a comparison can be made from one visit to another.