The precise definition of the procedure is as follows: the insertion of needles into painful points on the body without injecting any substance. It is used to treat painful musculoskeletal disorders, especially myofascial pain syndromes.

It is also applied to muscles, tendons and periosteum, but most often to myofascial trigger points. These myofascial trigger points are hyperirritable spots in the skeletal muscle, associated with hypersensitive, palpable nodules within a taut band. The spot is tender to pressure and can produce characteristic referred pain, motor dysfunction and autonomic phenomena.

First, you will discuss your symptoms with your therapist and locate the source of the pain. The therapist will then determine the point at which to apply the needle, disinfect the skin over that location and select an appropriate needle length. The insertion of the needle itself is painless. The procedure can continue in one of two ways. In the first, the needle is repeatedly pushed deeper and withdrawn without leaving the body, in order to elicit a so-called local twitch of the muscle. This is continued until the twitching subsides, or at the therapist's discretion. In the second, a mild electric current is passed through the needle into the muscle. Both methods produce a "reset" of the muscle.