Dry Needling
Dry needling is the use of solid filiform needles for therapy of muscle pain, sometimes also known as intramuscular stimulation. Acupuncture and dry needling techniques are similar. Although the needles used have been called “acupuncture needles” and were described as such in the Huang Di Nei Jing in the Han dynasty and at one time were manufactured for use by acupuncturists they are now more properly referred to as solid filiform needles and are used in both procedures. Dry needling contrasts with the use of a hollow hypodermic needle to inject substances such as saline solution, botox or corticosteroids to the same point. Such use of a solid needle has been found to be as effective as injection of substances in such cases as relief of pain in muscles and connective tissue. Analgesia produced by needling a pain spot has been called the needle effect.
Dry needling for the treatment of myofascial (muscular) trigger points is based on theories similar, but not exclusive, to traditional acupuncture; however, dry needling targets the trigger points, which is the direct and palpable source of patient pain, rather than the traditional “meridians”, accessed via acupuncture. The distinction between trigger points and acupuncture points for the relief of pain is blurred. As reported by Melzack, et al., there is a high degree of correspondence (71% based on their analysis) between published locations of trigger points and classical acupuncture points for the relief of pain. What distinguishes dry needling from traditional acupuncture is that it does not use the full range of traditional theories of Chinese Medicine. Dry needling would be most directly comparable to the use of so-called ‘a-shi’ points in acupuncture.
Technique
In the treatment of trigger points for persons with myofascial pain syndrome, dry needling is an invasive procedure in which a filiform needle is inserted into the skin and muscle directly at a myofascial trigger point. A myofascial trigger point consists of multiple contraction knots, which are related to the production and maintenance of the pain cycle. Deep dry needling for treating trigger points was first introduced by Czech physician Karel Lewit in 1979. Lewit had noticed that the success of injections into trigger points in relieving pain was apparently unconnected to the analgesic used.
Proper dry needling of a myofascial trigger point will elicit a local twitch response (LTR), which is an involuntary spinal cord reflex in which the muscle fibers in the taut band of muscle contract. The LTR indicates the proper placement of the needle in a trigger point. Dry needling that elicits LTRs improves treatment outcomes, and may work by activating endogenous opioids. Inserting the needle can itself cause considerable pain, although when done by well-trained practitioners that is not a common occurrence.[citation needed] No study to date has reported the reliability of trigger point diagnosis and physical diagnosis cannot be recommended as a reliable test for the diagnosis of trigger points.
Chan Gunn introduced a type of dry needling called intramuscular stimulation in the 1980s that moved away from using trigger points. Gunn believed that the peripheral muscle spasm was not the origin of pain, but instead a tight multifidi was causing spinal nerve compression, radiculopathy, and nerve damage running peripherally. This spinal nerve damage eventually reached the associated muscle, causing spasm and transformation to a trigger point. Therefore, Gunn recommended a needle be placed in the paraspinal muscles in addition to the distally affected muscle. Peter Baldry developed a version called superficial dry needling in 2005, in which the needle is inserted about 5–10 mm into the tissue above the trigger point. Baldry practiced deep dry needling until he had a patient in the early 1980s with a trigger point in his anterior scalene muscle. Baldry decided to only penetrate the skin for fear of puncturing a lung. Baldry has such success with this technique that he applied it throughout the body by simply puncturing the skin superficially over a trigger point without actually reaching it.