Biomechanical Effects of Plastic Heel Cup on Plantar Fasciitis Patients Evaluated by Ultrasound Shear Wave Elastography

Abstract

The plastic heel cup has been adopted to treat plantar heel problems for years. However, its mechanisms and biomechanical effects are yet to be fully understood. The purpose of this study was to investigate the effects of the plastic heel cup on the microchamber and macrochamber layers of the heel pad by comparing the stiffness (in terms of the shear wave speed) and thickness of these two layers with and without a plastic heel cup during static standing. Fifteen patients with unilateral plantar fasciitis were recruited. The shear wave speed and thickness of the microchamber and microchamber layers of each symptomatic heel pad during standing measured by ultrasound shear wave elastography were compared between conditions with and without a plastic heel cup. It was found that a plastic heel cup reduced the shear wave speed of the microchamber layer to 55.5% and increased its thickness to 137.5% compared with the condition without a plastic heel cup. For the microchamber layer, the shear wave speed was reduced to 89.7%, and thickness was increased to 113.6% compared with the condition without a plastic heel cup. The findings demonstrate that a plastic heel cup can help to reduce the stiffness and increase the thickness for both layers of the heel pad during standing, suggesting that the mechanism of a plastic heel cup, and its resulting biomechanical effect, is to reduce the internal stress of the heel pad by increasing its thickness through confinement.

Elasticity evaluation of the plantar fascia: A shear wave elastography study involving 33 early-stage plantar fasciopathy subjects

“…They assumed it was the larger cross-sectional area of the plantar fascia in the original region that made the tensile stress less sensitive to changes in tensile force. Additionally, other studies on plantar fascia elastography have focused on the screening accuracy, intra-and interobserver agreements, and other influencing factors (Gatz et al, 2020;Beydoğan and Yalçın, 2021;Lin et al, 2022).…”

“…It is estimated that approximately 2 million Americans suffer from plantar fasciopathy each year, corresponding to up to 10% of the population who experience plantar fasciopathy over the course of their lifetime (Martin et al, 2014). In both non-athletic and athletic populations, the prevalence of plantar fasciopathy significantly limits their physical activities and has a detrimental effect on health-related quality of life (Lin et al, 2022). Although imaging is not required for the diagnosis of plantar fasciopathy, it may help to rule out other alternate diagnoses of heel pain and establish the diagnosis if the termed diagnosis cannot be reached (Schneider et al, 2018).…”

Different orthotics in management of plantar fasciitis: a systematic review

“…However, comparative studies that evaluated efficacy between different types of orthotics used with planter fasciitis are limited. Some studies have investigated the use of prefabricated orthotics, while others have focused on custom-made orthotics (8,9). In addition, there is a controversy about the optimal design and material of orthotics for plantar fasciitis (10).…”

An exploratory study of dynamic foot shape measurements with 4D scanning system

“…The heel width increased 4.8% during walking compared to static stance with HWB. Heel cup is recommended to enclose the heel soft tissue by providing additional confinement for the heel 63 .…”