A trigger point is a painful knot in a tight band of muscle. A trigger point often causes pain to be felt in other areas, too. For example, a trigger point in the neck or upper back can cause pain in the head.
Trigger point injections are shots of medicine into these knots to help relieve the pain. The medicines are usually local anesthetics like lidocaine.
Trigger point injections are often part of plan that includes other treatments, such as muscle stretching and strengthening.