Trigger point injections are used to target painful, hyper-irritable muscle knots known as trigger points with injections that typically contain a local anesthetic, a corticosteroid, and saline. The local anesthetic, such as lidocaine, goes to work immediately to relax the irritated nerves in the area. At the same time, the steroid tackles the inflammation, which has a direct effect on pain. Trigger point injections are most commonly used to address myofascial problems almost anywhere in the body, including pain in the: •  Back •  Neck •  Shoulders •  Arms •  Legs