Uncovering the alterations in extrinsic foot muscle mechanical properties and foot posture in fibromyalgia: a case-control study.

Objectives: The aim of the study was to evaluate foot posture and the mechanical properties of extrinsic foot muscles in fibromyalgia.

Methods: Patients with fibromyalgia (n = 86) and age- and gender-matched controls (n = 41) were included in the study. Foot Posture Index (FPI), Beighton and Brighton criteria were used to evaluate static foot posture, joint hypermobility, and benign joint hypermobility syndrome (BJHS), respectively.