Trigger points are focal areas of spasm and inflammation in skeletal muscle. The rhomboid and trapezius back muscles, located in the upper back and behind the shoulder areas, are a common site of trigger points. Trigger points in these areas can cause neck pain, shoulder pain, and headache. In addition to the upper spine, trigger points can also occur in the low back or less commonly in the extremities.
A trigger point injection (TPI) is an injection that is given directly into the trigger point for pain management. The injection may be an anesthetic such as lidocaine (Xylocaine) or bupivacaine (Marcaine), a mixture of anesthetics, or a corticosteroid (cortisone medication) alone or mixed with lidocaine.