Acupuncture analgesia refers to a technique used to relieve pain by the insertion and manipulation of threadlike needles at specific areas of the body along peripheral nerves. Acupuncture has been practiced in China for over 2000 years but Western medicine was only introduced to this practice about 300 years ago.
How is Pain Perceived?
Nociceptors are pain receptors that are sensitive to tissue damage. Impulses from mechanical and thermal nociceptors are transmitted over large myelinated A-delta fibers which are found mainly on the superficial body regions and produce sharp pricking sensations when activated. Signals arising from polymodal nociceptors are carried by small unmyelinated C fibres which are found in deeper skin layers and most every other tissue and produce a dull aching pain over extended periods of time.
How does Acupuncture Relieve Pain?
The effects of acupuncture on alleviating pain are related to the release of endogenous opiates and to the stimulation of A-delta fibers blocking transmission from C polymodal nociceptors. The latter is referred to as the gate theory of pain. Endogenous opiates are morphine-like substances, which include endorphins, enkephalins and dynorphin, which act to reduce the sensation of pain in an individual. These chemicals achieve their pain-killing effects by binding to specific receptors in tissues involved in the perception of pain. Acupuncture has been shown to cause an increase in the body’s production of endogenous opiates. This has been proven by administering naloxone, a chemical which reverses the effects of endogenous opiates. When administered during acupuncture therapy the pain of the individual persists. When acupuncture alone is used there is pain relief.
Acupuncture requires appropriate acupoints for needle insertion. Acupoints are normally located through anatomical location, palpation (tender points), or by electrical means. Acupoints are often present in regions distant from the site of pain. For example, low back pain acupoints are not only found on the lower back, but also in the buttocks and legs. Needles are inserted 0.5 cm to 1.5 cm into the acupoints. After the needle is applied, varying manipulations can be applied to the needle. These include lifting, twirling, rotating, vibrating, heating or electrically stimulating the needle.
There are obvious benefits for the use of acupuncture in the treatment of many different medical conditions. Acupuncture is a worthwhile therapeutic procedure that, unlike many drugs, has no side effects and is cost effective. Acupuncture has withstood the test of time.