*2.4. Statistical Analysis*

Statistical analysis was performed to obtain the Pearson r correlation coefficient by linear regression between the calculated data and the ink-type AI. A correlation coefficient falling between 0.7–0.99 was categorized as highly correlated, while 0.4–0.6 was categorized as a moderate correlation, 0.1–0.39 was categorized as a low correlation, and 0–0.1 was categorized as extremely uncorrelated.

For the comparison between groups, the Mann–Whitney U Test was used for the between-group comparison of pressure parameters between flatfoot and normal foot type groups with the significance level set at alpha = 0.05.

The reliability analysis for examining the reliability of the proposed system when several measurements on the same subject was performed with the Intraclass Correlation Coefficient (ICC) with a two-way mixed model (ICC 3,1) and Cronbach's alpha coefficient.
