The cause of your muscle pain or spasms may be one or more trigger points. Your doctor may decide to inject the painful spots to relax the muscle. This can help relieve your pain. Relaxing the muscle can also make movement easier. Any muscle in the body can have one or more trigger points. Several injections may be needed in each trigger point to best relieve pain. These injections may be given in sessions 1 to 2 weeks apart. In some cases, you may not feel much change in your symptoms until after the third injection.You may then be able to exercise to strengthen the muscle and help it heal.