Association between elasticity of tissue and pain pressure threshold in the tender points present in subjects with fibromyalgia: a cross-sectional study.

Fibromyalgia (FM) is a multicomponent illness and despite its worldwide prevalence, a complete understanding of its aetiology and pathogenesis remains unclear. The goal of the study is to analyze the level of association between elastic properties of tissue measured by strain elastography (SEL) and pain pressure threshold (PPT) in the characteristic painful points described in patients suffering from FM. This was a cross-sectional, observational study. A sample comprised of 42 subjects with FM was recruited from a private care centre. The occiput, low cervical, trapezius, supraspinatus, paraspinous, lateral pectoral, second rib, lateral epicondyle, medial epicondyle, gluteus, greater trochanter, knee, and anterior tibial PPTs were bilaterally assessed using a standard pressure algometer and elastic properties of tissue were evaluated by SEL. Linear regression analysis showed significant associations between SEL and dominant trapezius PPT (β = 0.487, 95% CI [0.045, 0.930], p = 0.032) after adjustments for the age, body mass index, and menopause status (higher SEL and higher pain sensitivity). No significant associations between SEL and the other PPTs variables were found in women diagnosed with FM. The PPT of the dominant trapezius is associated with SEL measurements in subjects suffering from FM. More studies are required to fully explain the underlying mechanisms.