For Myofascial Pain

A trigger point injection is a simple procedure for chronic muscle spasms causing pain.

What are trigger points?

Trigger points are localized muscle spasms. Muscle spasms occur when muscles become tight (contracted) for too long. This causes a decrease in oxygen to the muscle. This prevents the muscle from healing.

What is myofascial pain?

Trigger points are a type of myofascial pain. Myofascial pain is caused by the muscle itself and/or the fascia (a type of connective tissue) that attaches to the muscle. Sometimes myofascial pain feels like muscle tension. Other times it can be severe pain. The pain can be in a small area. This is called local pain. The pain can also be in a large area. This is called referred pain.

Myofascial pain can occur in all body regions. The picture shows areas where trigger points can occur and where these trigger points can refer pain.

How do I know if I have trigger points causing pain?

If you have pain in one or more of these areas that has not improved in four weeks, you may have pain from a trigger point. Common tests such as x-rays or MRIs do not show if a trigger point is causing pain.

What is a trigger point injection?

In a trigger point injection, an anesthetic (numbing medicine) and sometimes corticosteroid (anti-inflamatory medicine) are injected into one or several of trigger points. The steroid is used to treat local inflammation of the muscle.

The injection can be used to diagnose or treat myofascial pain. The medication is injected to see if it temporarily lessens your pain. If it does, and helps you move better, it tells the doctor the trigger point is at least one of the causes of your pain.

What happens during an injection?

The doctor will locate your trigger point and then insert a small needle directly into the trigger point. When the doctor is sure the needle is at the correct place, the medicine will be injected.

What happens after an injection?

When you are ready to leave, the clinic will give you discharge instructions. You will also be given a pain diary. It is important to fill this out because it helps your doctor know how the injection is working.

It may help to move in ways that hurt before the injection, to see if the pain is still there, but do not overdo it. Take it easy for the rest of the day.

You may feel immediate pain relief and numbness in the region that was injected for up to six hours after the injection. This tells you the medication has reached the right spot.

Your pain may return after this short pain-free period, or may even be a little worse for a day or two. This is normal. It may be caused by needle irritation or by the corticosteroid itself. Steroids usually take two or three days to start working, but can take as long as a week. You can usually return to work the day after the injection, but always check with your doctor.

How long can I expect pain relief?

How long you can expect pain relief depends on how many areas are injured, and on the amount of inflammation.

Sometimes an injection can bring several months of pain relief, and then more treatment is needed. Other times, particularly if there is no underlying disc or joint problem, one injection brings long-term pain relief. If your pain is caused by injury to more than one area, only some of your symptoms may be helped by one injection. If this occurs, your pain physician will know several other treatments to help your pain.