Morphology and Mechanical Properties of Plantar Fascia in Flexible Flatfoot: A Noninvasive In Vivo Study

Abstract

Plantar fascia plays an important role in human foot biomechanics; however, the morphology and mechanical properties of plantar fascia in patients with flexible flatfoot are unknown. In this study, 15 flexible flatfeet were studied, each plantar fascia was divided into 12 positions, and the morphologies and mechanical properties in the 12 positions were measured in vivo with B-mode ultrasound and shear wave elastography (SWE). Peak pressures under the first to fifth metatarsal heads (MH) were measured with FreeStep. Statistical analysis included 95% confidence interval, intragroup correlation coefficient (ICC1,1), one-way analysis of variance (one-way ANOVA), and least significant difference. The results showed that thickness and Young’s modulus of plantar fascia were the largest at the proximal fascia (PF) and decreased gradually from the proximal end to the distal end. Among the five distal branches (DB) of the fascia, the thickness and Young’s modulus of the second and third DB were larger. The peak pressures were also higher under the second and third MH. This study found a gradient distribution in that the thickness and Young’s modulus gradient decreased from the proximal end to the distal end of plantar fascia in the longitudinal arch of flexible flatfeet. In the transverse arch, the thickness and Young’s modulus under the second and third DB were larger than those under the other three DB in flexible flatfoot, and the peak pressures under the second and third MH were also larger than those under the other three MH in patients with flexible flatfoot. These findings deepen our understanding of the changes of biomechanical properties and may be meaningful for the study of pathological mechanisms and therapy for flexible flatfoot.

Ultrasound Strain Elastography Reliability in the Assessment of the Plantar Fascia and Its Relationship with the Plantar Thickness in Healthy Adults: An Intra and Interobserver Reliability Study in Novice Evaluators

“…The aforementioned studies were not able to quantitatively measure the elasticity of the fascia, however quantitative studies showed that human tendons and ligaments have a similar elasticity to the plantar fascia [31]. In addition, a recent meta-analysis [23] study showed that the PF were less stiff in the plantar fasciopathy group than in asymptomatic subjects, and other studies have shown PF from subjects suffering from plantar fasciitis to be softer than those in healthy controls [32][33][34]. In this regard, our results showed similar values when assessing SEL in healthy plantar fascia; nevertheless, the level of association between PF elasticity and thickness was very low.…”

Non-invasive and quantitive analysis of flatfoot based on ultrasound

“…When the medial longitudinal arch changes, the characteristics of the plantar fascia will change accordingly. At present, there are many reports on the characteristics of plantar fascia in flatfoot ( Wang et al, 2019 ; Qian et al, 2021 ). However, to the authors’ knowledge, the characteristics of the plantar fascia angle (the angle between the plantar fascia and horizontal line) in flatfoot have not been reported to date.…”

Rehydration of the Tendon Fascicle Bundles Using Simulated Body Fluid Ensures Stable Mechanical Properties of the Samples

“…Tendons are connective tissues which transmit a load from muscles to bone and are often overloaded, resulting in injury and tendon rupture. Analysis of the mechanisms of damage and disease processes requires both in vivo and ex vivo testing [1][2][3][4][5]. For reliable research, ex vivo samples should correspond to their in vivo counterparts.…”