The term “trigger point” was coined by Dr Janet Travell and Dr David Simon in the 1950s. A trigger point is a local hardening of an area in a muscle that often hardens to such a degree that, when touched with your finger, or palpated, it feels almost solid, like something entirely separate from the muscle itself. (1)
But the trigger point is a real part of the muscle, not at all a separate entity. When the muscle is pressed upon the trigger point will slide slightly away from the point of touch, or palpation. In figure A we see the trigger point slide to the right.
Trigger points are also sometimes referred to as Trigger Zones, Trigger Spots and Trigger Areas. You will also see Myofascial Trigger Points frequently mentioned when discussing these devilish areas of your muscles. (2)
All of these terms refer to the same area, Trigger Points, which “are localized and sometimes extremely painful contractures (‘knots’) found in any skeletal muscle of the body.” (3)
“Trigger points…are described as hyper irritable spots in skeletal muscle that are associated with palpable nodules in taut bands of muscle fibers. Trigger point researchers believe that palpable nodules are small contraction knots and a common cause of pain.” (4)
That last sentence is probably one of the most telling of all. “Trigger point(s)…are…a common cause of pain.” All skeletal muscles of the body have trigger points, and each and every one of them is capable of causing pain.
The pain caused by trigger points may range from a minor annoyance to a pain that is so crippling and severe that it induces people to commit suicide to rid themselves of the agony caused by the trigger point.
One of the most recognizable trigger points lies in the upper trapezius muscle, which lies atop of the torso resting between one’s shoulder and neck.
The area in yellow in the diagram above shows a trigger point that lies in the upper trapezius muscle that most people will recognize. This area is one that frequently tightens up because of stress and is part of an area that people automatically massage to loosen the muscle up, especially when one is fatigued.
In addition to causing pain to the area immediately surrounding the trigger point, the trigger point will often cause referred pain to a completely different muscle. Trapezius trigger points will often refer pain to the sides (scalenes) of the neck, to the jaw and to the temple of the head, causing headaches. (5)
Despite the many areas of the body to which trigger points can refer pain, successful treatments are available assuming that one finds the proper medical professional.
(1) Color Atlas of Acupuncture, Body Points, Ear Points, Trigger Points, 2nd Edition; Authors: Hans-Ulrich Hecker, MD, Angelika Steveling, MD; Elmar T Peuker, MD; Joerg Kastner, MD; Kay Liebchen, MD. P 168.
(2) Myofascial Pain and Dysfunction: The Trigger Point Manual; Authors: Janet Travell, MD and David Simons, MD. p 8.
(3) Wikipedia, Myofascial pain syndrome, http://en.wikipedia.org/wiki/Myofascial_pain_syndrome, retrieved 10-18-2009.
(4) (3) Wikipedia, Trigger point, http://en.wikipedia.org/wiki/Trigger_points, retrieved 10-18-2009.
(5) Myofascial Pain and Dysfunction: The Trigger Point Manual; Authors: Janet Travell, MD and David Simons, MD. p 279.