Trigger point injection (TPI) is a technique used in the treatment of painful areas of muscle that contain trigger points. TPI is used to treat a wide variety of pain syndromes and other painful conditions.

In the TPI procedure, a health care professional inserts a small needle into the patient’s trigger point. The injection contains a local anesthetic or saline, and may include a corticosteroid. With the injection, the trigger point is made inactive and the pain is alleviated.