Trigger points are described as hyperirritable spots in the fascia surrounding skeletal muscle. They are associated with palpable nodules in taut bands of muscle fibers.(1) In other words, it feels like a knot in your muscle that is sensitive to pressure.
Many practitioners maintain that trigger points are separate entities from acupuncture points (acupoints). However, ashi (translated as ow yes!) points, described in The Yellow Emperor’s Classic and considered acupoints, exhibit pain upon palpation(2) and demonstrate characteristics identical to the Western concept of trigger points. Research has demonstrated that, when comparing 255 known trigger points to known acupuncture points, 92% of trigger points had anatomically corresponding acupoints. Interestingly, the characteristics of their referred pain patterns had complete or near-complete agreement with 76% of their corresponding acupoints, with another 14% having at least some agreement.(3)
Trigger points (TrPs) are extremely common and become a painful part of nearly everyone’s life at one time or another. Latent (inactive) TrPs, which often cause motor dysfunction (stiffness and restricted range of motion) without pain, are far more common than the active TrPs, which in addition cause pain.(1) Voluntary (skeletal) muscle is the largest single organ of the human body and accounts for nearly 50% of body weight. The Nomina Anatomica reported
by the International Anatomical Nomenclature Committee under the Berne Convention, lists 200 paired muscles, or a total of 400 muscles. Any one of these muscles can develop TrPs that refer pain and motor dysfunction, often to another location.
The severity of symptoms caused by TrPs ranges from the agonizing incapacitating pain caused by very active TrPs to the painless restriction of movement and distortion of posture due to latent TrPs that are so commonly overlooked.(1) The potential severity of pain from acute activation of a TrP is illustrated by one housewife who, while bending over cooking, activated a quadratus lumborum ( muscle in the low back) TrP that made her fall to the kitchen floor and caused pain so severe that she was unable to reach up and turn the stove off to prevent a pot from burning through its bottom.
The activation of a TrP is usually associated with some degree of mechanical abuse of the muscle in the form of muscle overload, which may be acute, sustained, and/or repetitive.(1) In addition, leaving the muscle in shortened position (eg: sleeping with your neck in a funny position) can convert a latent TrP to an active TrP and this process is greatly aggravated if the muscle is contracted while in the shortened position.
For a visual representation of this process watch this short but very informative video.
- Travel J, Simons D & Lois S. Myofascial Pain and Dysfunction: The Trigger Point Manual, (LWW: 1998), Chapter 1. Available at http://www.amazon.com/Myofascial-Pain-Dysfunction-Trigger-Manual/dp/0683083635
- Nugent-Head, Andrew. ―Ashi Points in Clinical Practice‖ in Journal of Chinese Medicine 101 (February 2013), pp. 5-12. https://www.jcm.co.uk/ashi-points-in-clinical-practice.html
- Dorsher, Peter T. MD. ―Trigger Points And Acupuncture Points: Anatomic And Clinical Correlations‖ in Medical Acupuncture Journal 17, Issue 3 (May 2006), pp. 20-23. http://myofascialtherapy.massagetherapy.com/trigger-points-and-acupuncture-points-medical-article