Trigger points are bands of muscle or palpable nodules which are painful points in the skeletal muscle. These points radiate unexplained pain. Pressing on a trigger point may elicit local tenderness, referred pain, or a twitch response.
Trigger point injection (TPI) may be an option for treating pain in some patients. TPI is a procedure used to treat painful areas of muscle that contain trigger points, or knots of muscle that form when muscles do not relax. Many times, such knots can be felt under the skin. Trigger points may irritate the nerves around them and cause referred pain, or pain that is felt in another part of the body.
TPI into these points may provide relief where other methods fail.