A Closer Look at Trigger Points

A trigger point (TrP) is a hyperirritable spot in a taught band of skeletal muscle that can refer pain to other parts of the body. These referred sensations can include pain, tingling, numbness, or burning.

There are trigger point charts that show exactly what muscle and TrP refers to which area of the body. Here are three different examples of trigger point charts showing the trapezius, rhomboid, and sternocleidmastoid (SCM) muscles and the pain referral pattern associated with them.  The X represents the trigger point and the red shaded area is the referred pain caused by the trigger point.

Trapezius Muscle


Rhomboid Muscle


Sternocleidmastoid (SCM) Muscle


There are also different types of trigger points which include Active, Latent, Primary, Secondary, and Satellite.

Active TrP: A trigger point that causes pain and will refer pain to other areas of the body.

Latent TrP: A trigger point that does not cause pain in the area or other areas of the body until pressure is applied to activate it.

Primary TrP: When the trigger point itself is painful. Now just because an Active TrP causes the pain does not mean the TrP is painful itself. Primary TrP’s can activate a Secondary TrP but not vice versa.

Secondary TrP: A TrP that became active because its muscle was overloaded by working with or against another muscle that contains the Primary TrP.

Satellite TrP: A TrP that became active because its muscle was located within the pain referral pattern of another trigger point.

Kim Sonsky