## 2 Materials and Methods
\begin{table}
\begin{tabular}{c c c} \hline
**Measuring System** & **Pedar® Insoles** & **Physiosensing® Platform** \\ \hline
**Device type** & Flexible insoles & Rigid platform of pressure \\ \hline
**Supplier** & Novel & Sensing Future Technologies. \\ \hline
**Number of sensors** & 99 sensors per insole & 1600 sensors on the platform \\ \hline
**Occupied area** & 1 cm\({}^{2}\) per sensor & 1 cm\({}^{2}\) per sensor \\  & & Active area: 40 \(\times\) 40 cm\({}^{2}\) \\ \hline
**Distribution** & Homogeneous & Homogeneous \\ \hline
**Sensor type** & Piezoresistive & Resistive \\ \hline
**Sensor characteristics** & Sensor thickness: 1.9 mm & \\  & Pressure range: 637.5 kPa & Maximum pressure: 100 N/cm\({}^{2}\) \\  & Histerese: 7\% & Frequency: 100 Hz \\  & Resolution: 2.5 kPa & Frequency: 50–100 Hz \\ \hline
**Insole size and platform area** & V 1872 R/V 1869 L & \\  & W1928 R/W 1927 L & \\  & X 2746 R/X 2747 L & \\  & XW 532 R/XW 533 L & \\ \hline
**Data acquisition** & -Connection to a computer (via cable & \\  & or _Bluetooth_) & -Connecting to a computer (via cable) \\  & -Registration on memory card for & \\  & later analysis & \\ \hline \end{tabular}
\end{table} 
Table 2: Technical characteristics of Pedar® insoles by Novel, and Physiosensing® platform by Sensing Future Technologies. The same conditions among all trials were defined in the test protocol and communicated to volunteers. It establishes the steps taken before data acquisition, the volunteers' posture, and the acquisitions' duration and interval. A Bluetooth connection was used for the Pedar(r) and the cable connection for the Physiosensing(r) system to establish a connection between a computer and the device. For the Pedar(r) System, the right insole size for the volunteer is determined, followed by the calibration process, which uses a memory stick with calibration data for the insoles. Concerning the Physiosensing(r) platform, the device is placed on the floor, 3.5 m from a wall. The data acquisition process was the same with both equipment, feet shoulder-width apart, torso vertical, arms along the body, and gaze directed at a previously marked point: 2.0 m high and 3.5 m away from the volunteer. Five valid acquisitions with a 30 s duration and a 30 s interval between acquisitions were collected. The values obtained in this study were evaluated to better understand the reliability between the two instruments (insoles and platforms). Later sections discuss these results in detail, where agreement on specific parameters is analyzed (MPP and contact area). All data was analyzed using Statistical Package for Social Science (SPSS(r)) software 25.0 (IBM(r) Corporation, New York, NY, USA). Descriptive statistics were used to summarize the sample average achievements. The normality of the distribution of the parameters was tested with the Shapiro-Wilk test. Plantar pressure results were compared using Student's t-test for paired samples. This analysis was complemented by evaluating the effect size using Cohen's d and Hedges correction. The Intraclass Correlation Coefficient (ICC) was used to assess the level of agreement between the Pedar(r) and Physiosensing(r) instruments regarding the measured parameters. According to [PERSON] and [PERSON] (2009) [38], ICC values inferior to 0.5 (<0.5) indicate poor reliability and suggest the instruments have significant discrepancies. From 0.5 to 0.75 indicates moderate reliability: an acceptable but still limited agreement was reached. From 0.75 to 0.9 reflects good reliability and satisfactory agreement for most applications, and then, higher than 0.9 (>0.9) represents excellent reliability and a high consistency between instrument measurements  
Figure 1: Summary of the qualitative and quantitative analyses carried out by the software Physiosensing®.