04/02/2021
What is a Trigger Point?
A trigger point (TrP) is a focal area of hyperirritability that is locally sensitive to pressure and can refer symptoms (usually pain) to other areas of the body. TrP's are reported to exist in most every soft tissue of the body, including muscle, muscular fascia, periosteum, ligament, and skin. The term myofascial TrP is used to describe TrPs that exist within skeletal muscle tissue or skeletal muscular fascia (usually the tendon or apo neurosis of a muscle). This text will restrict its discussion to myofascial TrPs, which are the most common type of TrPs found in the body.
Put simply, a skeletal muscle TrP is what the lay public refers to as a tight and painful muscle knot. More specifically, a skeletal muscle tissue TrP is a hyperirritable focal area of muscle hypertonicity (tightness) located within a taut band of skeletal muscle tissue. Furthermore, as with all TrPs, it is locally sensitive to palpatory pressure and can potentially refer pain or other symptoms to distant areas of the body.
All TrPs can be divided into two classifications, active TrPs and latent TrPs. Although the definitions are not fully consistent, it is generally agreed that latent TrPs do not cause local or referred pain unless they are first compressed, whereas active TrPs may produce local or referred pain even when they are not compressed. A latent TrP is essentially at a less severe stage than is an active TrP, and if left untreated, a latent TrP often develops into an active TrP.
Furthermore, myofascial TrPs are often divided into central TrPs and attachment TrPs. As their names imply, central TrPs are located in the center of a muscle (or more accurately, in the center of muscle fibers) and attachment TrPs are located at the attachment sites of a muscle.
Effective clinical treatment of clients who present with myofascial pain syndromes requires an understanding of both why TrPs form in the first place and what the essential mechanism of a TrP is.
