Dry needling is a technique physical therapists use (where allowed by state law) to treat pain and movement impairments. The physical therapist inserts a “dry” needle, one without medication or injection, into areas of the muscle.

Dry needling is not acupuncture, which is based on traditional Chinese medicine performed by acupuncturists. Dry needling is a part of modern Western medicine and is supported by research.

When your muscle is overused, it goes into an energy crisis where the muscle fibers aren’t getting an adequate blood supply. When they don’t get the normal blood supply, they don’t get the oxygen and nutrients that allow your muscle to go back to its normal resting state.

When this happens, the tissue near your trigger point becomes more acidic. Your nerves are sensitized, which makes the area sore and painful.

Stimulating a trigger point with a needle helps draw normal blood supply back to flush out the area and release tension. The prick sensation can also fire off nerve fibers that stimulate your brain to release endorphins, your body’s homemade pain medication.

Once your therapist locates a trigger point, they’ll insert a needle through your skin directly into it. They might move the needle around a little to try to get what’s called a local twitch response — a quick spasm of your muscle. This reaction can be a good sign that your muscle is reacting.

Some people feel improvement in their pain and mobility almost immediately after a dry needling session. For others, it takes more than one session.