The weight-bearing plantar ultrasound imaging device (WPUID) was developed to allow evaluation of the plantar coronal structure during weight-bearing (Fig. 1a). A solid 1 cm × 10 cm gel block (SONAGEL; Takiron Co. Ltd., Osaka, Japan) for ultrasound scanning and a digital weight scale (HD-660; Tanita, Tokyo, Japan) was integrated into the surface of the WPUID platform (Fig. 1a). A 92 mm-wide linear 5 to 10 MHz probe (EUP-L53L; Hitachi.
Ltd., Tokyo, Japan) was affixed directly beneath the solid gel block perpendicular to the platform surface (Fig. 1b). A Noblus ultrasound machine (Hitachi. Ltd., Tokyo, Japan) was also connected to the WPUID. According to the design of the device, one forefoot has to be placed on the solid gel block for ultrasound evaluation and the other foot has to be situated on the digital weight scale to adjust the load on each foot. This device was previously used in other studies [13] [14] [15] 27] .
Ltd., Tokyo, Japan) was affixed directly beneath the solid gel block perpendicular to the platform surface (Fig. 1b). A Noblus ultrasound machine (Hitachi. Ltd., Tokyo, Japan) was also connected to the WPUID. According to the design of the device, one forefoot has to be placed on the solid gel block for ultrasound evaluation and the other foot has to be situated on the digital weight scale to adjust the load on each foot. This device was previously used in other studies [13] [14] [15] 27] .