Clinical term

Trigger point

A trigger point is a highly sensitive spot located within a taut band of muscle; pressing it can reproduce a familiar pain and sometimes pain felt at a distance (referred pain).

Scientific basis

An international expert consensus retains three main criteria: a taut band within the muscle, a hypersensitive spot within that band, and the person's recognition of their usual pain when the spot is pressed (Fernández-de-las-Peñas and Dommerholt 2018). A classic distinction is made between active trigger points, which reproduce spontaneous pain, and latent trigger points, which are painful only under pressure.

Microdialysis measurements have shown higher concentrations of substances associated with pain and inflammation at active trigger points (Shah et al. 2008). However, the reliability of locating them by palpation varies with the criteria used, the examiners and their training (Lucas et al. 2009), and both their nature and their causal role in pain remain debated (Quintner et al. 2015).

Trigger points of the pelvis. Trigger points are described in muscles of the pelvis and hip, such as the piriformis, the obturator internus and the pelvic floor muscles. Their presence is not enough to explain pelvic pain, which calls for a medical evaluation.

Blue Portance / SBNFA™ reading

In the SBNFA™ reading, a trigger point is a local indicator of muscle sensitivity and tension, to be read in the context of muscle tone, protective strategies and the loads the tissue is subjected to. An observed tension or sensitivity is an indicator, not a sufficient explanation.

Contribution to the analysis of sitting

Seating analysis does not locate trigger points. It describes the distribution of support, the orientation of the pelvis and the possibilities for variation, which change the demands placed on certain muscles in the seated position; examining the muscles is a matter for a health professional.

Not to be confused with

Myofascial pain syndrome, a pain picture in which trigger points are described; Hypertonia, increased tone or resistance of a muscle, with no localized spot required; Contracture, an involuntary and sustained contraction; Fibromyalgia tender point, a sensitive spot without a taut band or referred pain, a former classification criterion; Acupuncture point; Allodynia and hyperalgesia, changes in pain sensitivity.

Sources and scope

An established yet debated clinical construct, with no unified diagnostic criteria; not a disease in its own right. A trigger point is not a demonstrated cause of pain, does not on its own explain pelvic pain, and "releasing" a trigger point does not address the cause of pain. No seat eliminates trigger points.