Intramuscular stimulation (IMS), also known as trigger point dry needling, is one of my favourite tools to use in practice. It is not the same as acupuncture, which is based on Traditional Chinese Medicine. Dry needling is a modern Western medicinal approach that is supported by research and involves the application of thin/fine needles into tightened and shortened bands of muscle. It is "dry" because no medication or substance is injected into the skin.
If the muscle is normal, you may not even feel the needle penetrating the skin; however, if the muscle is tight, short, or full of scar tissue or trigger points, a unique sensation is felt. To me, it feels like a crampy (is that a word?) ache or Charley horse; others might describe them as twitches. This distinctive type of discomfort is caused by a tight muscle grasping the needle and then subsequently relaxing. People don't generally feel the needle at all, but it's the muscle cramping/twitching that's uncomfortable. As unpleasant as it sounds, patients soon learn to recognize and welcome the sensation as it represents "good pain" when the muscle releases and no longer feels tight.
Dry needling is an invasive procedure which allows for the stimulation of underlying myofascial trigger points that regular manual therapy or massage therapy cannot reach or target. Interestingly, I've learned to palpate or feel for muscle tone/resistance using just a needle, as if the needle becomes an extension of my hand to feel deep inside the muscle tissue. The goal of IMS is to release or inactivate trigger points that may be causing pain or dysfunction in the body. The results of IMS are (almost) instantaneous, and the effects are cumulative. With each session, needling stimulates a certain amount of healing in the body until eventually, the muscle fully heals itself.
Many people know what acupuncture is, but not many know about dry needling. Everyone's experience with IMS is different: some find it quite uncomfortable and aren't able to tolerate more than a few seconds of it; others don't mind it at all and are willing to put up with some temporary discomfort to see lasting results. With all that said, I do have a lot of patients that come back asking for IMS (even though they hate every second of it) because it works well, and they value the end result over temporary discomfort.
As with any physiotherapy modality, dry needling is rarely done as a standalone treatment. There is always a reason why muscles become tight, so it is important to identify the causes of these trigger points in order to prevent recurrences. IMS may be performed in conjunction with other manual therapy, electrotherapeutic modalities, and exercise programs.
