# A Simple Foot Plantar Pressure Measurement Platform System Using Force-Sensing Resistors
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**No.**} & \multicolumn{10}{c}{**Load Per Sensor (Gram)**} & \multicolumn{10}{c}{**Total Load**} \\ \cline{2-13} \multicolumn{1}{c}{**Subject**} & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **13** & **14** & **15** & **Sensor (kg)** \\ \hline
1 & 702 & 210 & 290 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 350 & 302 & 540 & 342 & 787 & 3.5 \\
2 & 644 & 517 & 437 & 527 & 0 & 363 & 0 & 169 & 0 & 426 & 526 & 429 & 514 & 398 & 516 & 5.5 \\
3 & 727 & 583 & 657 & 623 & 0 & 654 & 196 & 454 & 0 & 474 & 643 & 627 & 688 & 592 & 766 & 7.7 \\
4 & 731 & 617 & 710 & 686 & 0 & 690 & 0 & 318 & 0 & 457 & 522 & 449 & 673 & 601 & 257 & 6.7 \\
5 & 694 & 441 & 662 & 547 & 0 & 557 & 0 & 249 & 0 & 612 & 489 & 278 & 665 & 558 & 424 & 6.2 \\
6 & 736 & 700 & 641 & 476 & 0 & 373 & 0 & 0 & 0 & 470 & 438 & 263 & 634 & 471 & 354 & 5.6 \\
7 & 706 & 571 & 606 & 550 & 0 & 428 & 0 & 0 & 2 & 283 & 453 & 474 & 723 & 705 & 705 & 6.2 \\
8 & 776 & 561 & 467 & 355 & 0 & 334 & 0 & 11 & 0 & 467 & 689 & 545 & 699 & 542 & 756 & 6.2 \\
9 & 764 & 574 & 493 & 435 & 0 & 392 & 0 & 0 & 370 & 332 & 325 & 0 & 784 & 656 & 686 & 5.8 \\
10 & 654 & 455 & 542 & 540 & 0 & 576 & 0 & 0 & 418 & 270 & 0 & 0 & 578 & 392 & 681 & 5.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Load data on the soles of left leg 10 research subjects. The asymmetry of the foot between the left and right leg can be known from by calculating the asymmetry index (ASI) using the following formula [20]:  
\[\text{ASI}=((\text{DL - NDL})/\text{DL})\times 100 \tag{2}\]  
where DL and NDL are dominant and non-dominant leg respectively and the right leg used as the basis calculation. The term DL is only to describe the load on the sole of one foot is greater than the other. From the calculation of ASI (%), as shown in Table 5, almost all subjects showed that standing on the right foot was more dominant than the left foot, seen from the positive ASI value in all areas of the sole of the foot. Significant differences in negative ASI values were seen in the thumb finger area of subjects' numbers 9 and 10. This could be due to the two subjects not really standing straight when measured. The fact that almost all subjects were more dominant with their right foot than with their left foot when standing can be seen from the total load of all sensors (last column in Table 5). There is  
Figure 4: Method of measurements static load of foot (**a**) and display result (**b**). Note: [PERSON] (Right Foot) and [PERSON] (Left Foot). no previous research that proves when standing the right foot is more dominant than the left foot except when they jump high during playing volleyball and basketball [20]. The measurement results obtained from the proposed low-cost measurement instrument used in this study are compared with Multi Array Foot Pressure (MAFP) measurement research result [21] that consisting of 625 FSR 400 sensors, as shown in Figure 5. The red color indicates the greatest load of foot while the least load represents by the dark blue color. The purpose of this comparison is not on validity of the value of load on the soles of each subject, but rather on the validity of the area of the affected foot and weight distribution pattern that occurs for each type of foot sol  
Figure 5: MAFP tool research results that also used in previous study by [PERSON] et al. [21].