*4.1. Placements of the Sensors*

To the best of our knowledge, the majority of previous papers have suggested the placement of the force sensitive resistance (FSR) for some specific reference sites of the foot itself, such as the lateral arch and forefoot [18,21]. The current study proposed a more general guideline for the placement of the FSR relative to a given anatomy site, like the commonly targeted medial arch taken in the current study, by describing the placement site in terms of percentage of the insole along the length of the insole itself, which copes with the size of the participant's foot. The established FSR placement indication on the insole could also help provide guidelines regarding the placements of the FSR from a single one to numerous ones according to the needs for clinical application during the current and future development of the prototype. Based on this repeatability consideration, the author could then perform the human testing that aimed to first perform the correlation between traditional AI and the value of each point, which is a new way to define the placement of the sensor in this study to find out the position of the effective plantar pressure sensor. In addition, unlike the aims of those previous research and development studies reported in the literature, the current study aimed to compare whether there were significantly different values obtained from sensors at specific positions between the flatfoot and normal foot using the data of 21 young subjects.
