# A Simple Foot Plantar Pressure Measurement Platform System Using Force-Sensing Resistors
## 3 Results and Discussion  
In the early stages of this measuring instrument prototype, 10 students from the Department of Mechanical Engineering, Diponegoro University participated in the study. Details on the subjects in the study are presented in Table 2. The weight and height were measured with body mass index (BMI) digital tools [17]. While FL, the contact area of the foot (FAC: Foot contact) and foot type (high arch, normal, flat foot) were measured by digital footprint tools [18]. From the FL data, sensors in each area of the measuring instrument (rear foot area, mid foot, without the toes of the foot, and thumb fingers) are still in the same area on the foot of the entire subject, as presented in Table 2. This indicates that each foot area of all subjects with shoe size of 40-42 has similar measurement within the sensors on the rear foot area (sensor 1-3), mid foot area (sensor 4-7), front foot area (sensors 8-14), and thumb finger area (sensor 15).According to the FAC data, it is shows that the average FAC for males are larger than females, which are 12,806.8 mm\({}^{2}\) and 11,310.1 mm\({}^{2}\), respectively [2,19]. There are five subjects with a high arch foot type, three normal arch subjects, and two low arch subjects. It is called high arch when AI \(\leq\) 0.21, normal arch when 0.26 \(\geq\) AI \(>\) 0.21, and low arch when AI \(>\) 0.26, where AI is the Arch Index as defined by [PERSON] [5]. The data of the load measurement results in each sensor is presented in Tables 3 and 4 for the soles of the left and right foot, respectively. The measuring result proves the burden on the soles of women's feet is greater than that of men [2]. It is seen from the magnitude of the total sensor load ratio \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline \multicolumn{11}{c}{**On the Left and Right Leg Soles (cm)**} \\ \hline  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **13** & **14** & **15** \\ \hline x1 & 0.0 & 1.5 & \(-\)1.5 & \(-\)1.5 & 1.0 & \(-\)2.0 & 1.5 & \(-\)0.6 & \(-\)3.5 & \(-\)3.0 & \(-\)0.5 & 2.0 & \(-\)0.6 & 2.0 & 2.3 \\ x2 & 0.0 & \(-\)1.5 & 1.5 & 1.5 & 1.0 & 2.0 & \(-\)1.5 & 0.6 & 3.5 & 3.0 & 0.5 & \(-\)2.0 & 0.6 & \(-\)2.0 & \(-\)2.3 \\ y & 3.8 & 6.5 & 6.5 & 9.0 & 9.5 & 11.5 & 12.0 & 13.5 & 13.5 & 16.0 & 16.5 & 16.5 & 19.0 & 19.5 & 23.4 \\ \hline \end{tabular} Description: x1 and x2 are local coordinates x left and right foot soles.  
\end{table} 
Table 1: The coordinate placement of the sensors. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**No.** & **Gender** & **Weight** & **High** & **BMI** & **FL** & **Shoe** & **FAC** & **Foot** \\
**Subject** & **(M/F)** & **Agency (kg)** & **Agency (cm)** & **(kg/m\({}^{2}\))** & **(mm)** & **Size** & **(mm\({}^{2}\))** & **Type** \\ \hline
1 & M & 52.8 & 171 & 18.1 & 250.0 & 40 & 8505.6 & HA \\
2 & F & 64.8 & 175 & 21.2 & 258.0 & 42 & 12,392.0 & NA \\
3 & M & 68 & 166 & 24.7 & 257.0 & 42 & 14,204.3 & LA \\
4 & M & 71.5 & 171 & 24.3 & 249.1 & 40 & 14,332.1 & NA \\
5 & M & 84.7 & 173 & 28.4 & 255.8 & 41 & 14,954.0 & LA \\
6 & M & 75.2 & 168 & 26.6 & 255.5 & 41 & 12,038.1 & NA \\
7 & F & 71.6 & 168 & 25.5 & 252.0 & 41 & 11,451.4 & HA \\
8 & F & 54.4 & 170 & 18.8 & 254.5 & 41 & 12,221.8 & HA \\
9 & F & 54.7 & 167 & 19.7 & 249.2 & 40 & 9456.1 & HA \\
10 & F & 55.8 & 174 & 18.4 & 255.7 & 41 & 11,029.1 & HA \\ \hline \end{tabular} Note: high arch (HA); normal arch (NA); low arch (LA) (flat foot).  
\end{table} 
Table 2: A detail information of participated subjects in this study. Figure 3: Block diagram system of static load gauge of soles. against 0.5 BW (%), i.e., for the left leg: 16.8% male and 19.3% female and right foot: 22.7% male and 23.2% female. It is also indicated in the measurement that majority of the subjects were right-footed. This is also the evident from the previous study that described the total load difference of the average sensor at the right-footed greater than 21.9% compared to the left foot [19].