A trigger point is a tight knot that develops in a muscle or the fascia, which is the connective tissues covering your muscles and organs. You can develop a single trigger point, or several knots, along a band of muscles. If your trigger point causes chronic pain, the condition is called myofascial pain syndrome.
There are two types of trigger points:
Active trigger points
Active trigger points are very sensitive and painful, often causing pain even when you’re resting. You may also develop muscle weakness, limited movement, and referred pain, which is pain that’s felt elsewhere in your body when the trigger point is pressed. Pressure on the trigger point may also cause an automatic muscle twitch.
Latent trigger points
Latent trigger points may hurt when you press on the knotted area, but they’re less painful than active trigger points.
Trigger points are usually caused by:
- Repetitive muscle movements
- Lifting heavy weights or items
- Direct injury
- Poor posture
- Tense muscles
Although trigger points most often develop due to overusing or placing excessive stress on your muscles, they can also occur if you stay inactive for too long.
A trigger point injection contains a local anesthetic. The local anesthetic blocks pain signals, providing immediate relief. Steroids alleviate pain by reducing inflammation. It takes several days to feel the effect of steroids, but they provide longer-lasting relief.
During a trigger point injection, your doctor finds the trigger point, and may apply a topical anesthetic on the skin above the knotted muscle. Then the needle is inserted into the trigger point and the medication is injected. If the trigger point doesn’t fully relax after one injection, your doctor may slightly reposition the needle and deliver another injection.