A trigger point is a very tender area, usually near the insertion of a muscle or ligament or near a joint, and usually relatively small or well-localized.
When trigger point pain is severe and non-responsive to conservative measures, injection with local anesthetic, with or without added steroid, may be helpful.
Trigger points may be injected with tiny (25-gauge) needles of variable length placed through the skin and into the substance of the muscle. Risk is minimal, and discomfort on injection can be minimized with a cold spray of Fluoro-Methane.
One to five trigger points may be injected in one session, and sessions are typically repeated at regular intervals in a series and coordinated with physical therapy. Injections that relieve pain allow greater participation by the patient in stretching programs, aerobic exercise programs, and other physical therapy treatments.