What are trigger point injections and how do they work?

A trigger point is a distinct, very tender band within a muscle that you can feel with the fingers. When pressed, it brings on a person’s familiar pain. The injection places a small amount of local anesthetic, sometimes with dry needling of the band itself. The goal is to interrupt the contracted segment.

The mechanism is mechanical and neurological, not anti-inflammatory. Needling breaks up the taut band. The anesthetic interrupts the pain-spasm loop long enough for normal movement to come back.

When are trigger point injections worth doing?

• A clearly palpable (easy to feel), reproducible trigger point that recreates your specific pain.
• Myofascial pain (pain from muscle and its covering) that has not responded to manual therapy and movement work.
• As an add-on that opens a window for rehabilitation, with the rehabilitation actually scheduled.
• As a diagnostic step when it is unclear how much of the pain comes from muscle.

When are trigger point injections the wrong choice?

As a standing monthly visit with no end point. As a substitute for finding the joint, disc or nerve the muscle is guarding. And as the entire treatment plan for someone whose exam has never been done properly.

Muscles rarely become painful without a reason. Lasting trigger points in the lumbar paraspinals (the muscles along the low spine) are often secondary to a facet joint or a sacroiliac joint. That joint is doing something the muscle is trying to protect. Inject the muscle and you get relief that lasts until the guarding restarts. That is not so much a failure of the injection as a failure of the reasoning behind it. Why muscles guard.

What happens during a trigger point injection?

What are the side effects of trigger point injections?

The risks are low: soreness, bruising, and rarely infection. In the thoracic region (the mid-back) and in thin patients, needle depth matters because of the pleura (the lining around the lungs). That is a real if uncommon concern. It belongs in the consent talk, not in a reassurance.

Frequently asked questions

How long does relief last?

Days to a few weeks, typically. Longer when the underlying driver has been addressed alongside. Shorter when it has not.

Is dry needling the same thing?

A similar mechanism without the anesthetic. Evidence for the two is broadly comparable. The choice is often practical.

How many can I have?

There is no fixed number and no course here. Each one is a decision based on what the previous one achieved. A series with no lasting change is a signal to change the plan.

Do trigger point injections actually work?

They work for what they treat: a tight, tender band of muscle that brings on your familiar pain. The needle breaks up the band. The anesthetic interrupts the pain-spasm loop long enough to move normally. They fall short when the muscle is guarding a facet or sacroiliac joint. Relief then lasts only until the guarding restarts. So the plan has to address the joint too.

What medicine is used in a trigger point injection?

A small amount of local anesthetic, placed into the tender band through a fine needle, sometimes with dry needling of the band itself. No sedation is needed. The effect is mechanical and neurological, not anti-inflammatory. The needle breaks up the contracted segment. The anesthetic quiets the pain-spasm loop so normal movement can come back.

What should I do after a trigger point injection?

Move. The injection opens a window when the band is quiet. The point is to bring back normal motion during it, ideally with rehabilitation already scheduled. Without that movement the band simply tightens again. Expect soreness for a day or two, sometimes more than before the injection. Do not read that soreness as failure.

Do trigger point injections hurt?

Briefly. The band is found by pressing on it, then a fine needle delivers local anesthetic without sedation. A quick twitch in the muscle is common and is a good sign the band was engaged. Soreness for a day or two afterward is normal. Bruising is possible, and infection is rare.

Related reading

• Back spasms
• When injections stop working
• Physical therapy for back pain
• The diagnostic block