Gunn Intramuscular Stimulation (IMS)

What is IMS?

IMS, or Intra-Muscular Stimulation, is a dry needling method developed by Canadian physician Dr. Chan Gunn in which an acupuncture needle is inserted into “trigger points” in the muscle. These trigger points are localized, taut bands of muscle that are usually hyperirritable¹ meaning that it is likely to cause pain^1,2. But how would stabbing a sore muscle with a needle make it feel better? This can be explained using Dr. Gunn’s model, which is based on radiculopathy. Radiculopathy is basically a fancy way of saying that muscle/myofascial pain is the result of the disorder of peripheral nerves¹. The areas around these nerves develop a “super sensitivity” that is manifested in your muscles as muscle shortening and the development of taut bands (knots in the muscle) as well as pain². Knots in the muscle can add further pressure on the nerve leading to more pain, irritability, atrophy, and sensitivity¹. Essentially these knots in your muscles lead to a vicious cycle of restricted nerve impulses, decreased blood flow, and pain.

How does it work?

When the acupuncture needle is inserted into the “trigger point”, the muscle responds with local twitches or “jumps”. These twitches can be thought of as an electrical reset of the nerve root that innervates that muscle. After the needle is removed, the electrical activity of those unwell nerves is reduced¹. In other words, the overactive “unhealthy” nerves relax and normal flow or nerve impulses is restored. This results in decreased pain, muscle relaxation and decreased dysfunction!

What does it feel like?

When the acupuncture needle is first inserted it feels like a mosquito bite or a tiny pinprick. The jumps or twitches feel like quick muscle cramps, which can be slightly uncomfortable. After treatment, normal side effects include muscle soreness and possibly some bruising around the treatment site. The soreness that is experienced is a muscle soreness; similar to the way your muscle feels after a hard workout.

Is IMS the right treatment for me?

IMS is an excellent treatment option for a number of pathologies. If you are experiencing any of the following common diagnoses (or if you just enjoy needles), IMS could be a beneficial treatment for you:

If you are experiencing continuous dull aching pains, tender and tight knots in your muscles, or have a limited range of motion, IMS could be the treatment that finally works for you. The severity of the injury and how your body responds to the treatment can dictate how many sessions are necessary.

IMS is a can be extremely effective when used as a part of a complex treatment regime. It is minimally-invasive and carries a very low risk.

Want to learn more?

You can visit:

• UBC Gunn IMS website
• Check out our Gunn Intramuscular Stimulation service page on our site
• Or you can come and speak to one of our excellent physiotherapists!

References

1. Klichman L, Vulfsons S. Dry needling in the management of musculoskeletal pain. J. Am Board Fam Med. 2010 September;23(5):640-646
2. Dommerhold J, del Moral OM, Gröbli C. Trigger point dry needling. J. of Manual & Manipulative Therapy. 2006 January;14(4):70-87