I don’t like wading into this discussion. It bothers me that this discussion even exists. Sometimes, though, we must do things we don’t really want to do to get someplace we’d like to be. So, here we are. I’ve commented on the dry needling issue before, if you like you can go back to my post history on my Facebook business page and see what I’ve said previously.
Let’s start out with the dry needling side of the equation. What is it, why does it exist, and why is it called ‘dry needling’?
In the first half of the 20th century, there were many doctors around the world researching pain (1). Some of them were looking at the myofascial (muscle and connective tissue) system as a source of certain kinds of pain. At least two of them, Janet Travell and David Simons, eventually formalized this work (with a physical therapist co-author, Lois Simons) into a two-volume set titled “Myofascial Pain and Dysfunction: The Trigger Point Manual”.
Short side-trek: what’s a trigger point? Straight from Simons, Travell, and Simons, a clinical trigger point is “A hyper-irritable spot in skeletal muscle that is associated with a hypersensitive palpable nodule in a taut band. The spot is painful to compression and can give rise to characteristic referred pain, referred tenderness, motor dysfunction, and autonomic phenomena.” (1)
Simons, Travell, and Simons go on to describe trigger points from an etiological (cause or set of causes) point of view. To wit “A cluster of electrically active loci each of which is associated with a contraction knot and a dysfunctional motor endplate in skeletal muscle.” (1)
Trigger points are typically divided between “active trigger points” and “latent trigger points” (1). An active point, as you might imagine, is a spot that is actively causing pain or discomfort (1). A latent point is a spot that is only reactive or painful upon compression (1).
Right away, we can see a few things. First, trigger points deal with muscle pain. Other kinds of pain can certainly cause trigger points through compensation but correcting those trigger points does nothing for the initial cause of the pain if the pain is not actually myofascial in origin.
Second, trigger points generally cause a referred pain pattern on compression or palpation. These referral patterns have been mapped out for specific points on specific muscles and help us to diagnose which muscle is having a problem. For example: I often get people in my clinic who have low back pain that radiates into the same side groin or inguinal crease. There are two muscles that typically radiate pain into the groin and only one of those two is in the low back. By understanding the muscular system and the radiating patterns we can narrow the field to the likely culprit and provide effective treatment.
Third, trigger points are often associated with a dysfunctional motor endplate in the muscle. The motor endplate (also called the neuromuscular junction) is the point where the primary nerve affecting that muscle enters the muscle tissue. This is telling us that the root problem is very often not the trigger point itself, rather it’s the motor endplate. Treating the trigger point can provide some relief. Treating the motor point often provides much longer lasting relief.
Now that we know what a trigger point is, why is it called ‘dry needling’? Acupuncture doesn’t become widely known in the US until the 1970s. Since acupuncture wasn’t as commonly practiced, acupuncture needles weren’t easily available. One of the initial treatments developed for trigger points involved injecting them with sterile saline (1). At some point, someone noticed that the syringe needle itself caused an effect which made the muscle relax. Eventually, treatment was provided by either using pressure (usually fingers) on the point or using an empty syringe with the plunger depressed - hence “dry” as nothing was injected. Later, in the 1980s and 90s it was discovered that an acupuncture needle would also give the same effect (1). Acupuncture needles also had the advantage of being much more comfortable.
Dry needling, then, is the insertion and removal of a needle in a point of high muscular tension creating a typical radiating pain pattern for that muscle. You’ll notice this constitutes a narrow clinical window. If it’s not muscular pain, dry needling is unlikely to help. If the point is tender but doesn’t create a radiating pain pattern typical for that point on that muscle, dry needling is unlikely to help. If the needle is retained, inserted in a location that isn’t a trigger point, inserted in a location that is distant to the trigger point, or if electricity is applied, we’re no longer talking about dry needling, we are firmly in acupuncture territory.
1. Simons, D., Travell, J., Simons, L. (1999). Myofascial Pain and Dysfunction: The Trigger Point Manual Volume 1. Upper Half of Body. Williams & Wilkins, Baltimore, MD