Table 1.
Risk related characteristics of the participants.
Fig 1.
Measuring and custom-made insoles fabrication process.
Specific interchangeable insole sandals used in the experimental setup (a). CAD-CAM milling process (b). CAD-CAM_CMI hand-finished by the application of a PPT top cover (c). Foam box impression with marked at-risk areas (d). Individual positive plaster moulds (e). Vacuum formation (f). Manufactured TCCI hand-finished by the application of a PPT top cover (g). Reprinted under a CC BY license, with permission from Guantificio Altotiberino ECOSANIT Calzature Snc, Anghiari, Italy, original copyright 2020.
Fig 2.
Patient’s blueprint with related at-risk locations.
Example of the recorded blueprints with related at-risk locations (i.e. callosities and sites of previous ulcers).
Fig 3.
CAD-CAM Software for foot orthoses design.
The ECOPLAN software combines shape and pressure data allowing the superimposition of the shape and pressure contours onto an outline of the intended insole perimeter. The offloading technique used is the removal of material under the high-pressure area. An automated design algorithm identifies the high-pressure contours along which the 3D scan shape is modified, creating a deepening area of the insole underneath regions of excessive local pressure (>200 kPa). Reprinted under a CC BY license, with permission from Guantificio Altotiberino ECOSANIT Calzature Snc, Anghiari, Italy, original copyright 2020.
Fig 4.
Optimal offloading performance case.
Assessed R-ROIs (yellow squares) and the underfoot pressure redistribution (white squares) induced by the insoles obtained for one subject in the 3 considered conditions. The picture on the left side presents three rows, three panels each, showing the comparison for the three considered conditions, respectively. The sequence from left to right shows TCCI vs FI vs CAD-CAM_CMI, respectively. The upper row (A) shows the results of the R-ROIs identification procedure and the t-Test to detect the pressure redistribution. In the top left corner of each picture, it can be seen the computed value of the total surface (cm2) of the determined R-ROIs. The white squares have to be interpreted considering the comparing pairs FI vs TCCI and FI vs CAD-CAM_CMI representing all and only the cells statistically different between the two conditions using the paired t-Test. The panels in the middle (B) and lower (C) rows show the mean peak frames in two different graphical representations. The middle row (B) shows a 5mm x 5mm cell discretisation level. The lower row (C) shows high resolution interpolated graphical images. On the right side, the recorded blueprints with the previously marked clinical at-risk locations (i.e. callosities and sites of previous ulcers) are superimposed on the zoomed FI related images. On the top are highlighted the computed value of the R-ROIs total surface per each foot. Reprinted under a CC BY license, with permission from Bioengineering & Biomedicine Company Srl, Pescara, Italy, original copyright 2020.
Fig 5.
Sub-optimal offloading performance case.
Assessed R-ROIs (yellow squares) and the underfoot pressure redistribution (white squares) induced by the insoles obtained for one subject in the 3 considered conditions. Red squares are introduced, and they represent those cells that belong to R-ROIs, for which no statistical difference has been detected by the paired t-Test between pairs of conditions. The sequences of the panels and their meaning are the same as in Fig 4. In this case, the custom-made insoles either TCCI or CAD-CAM_CMI were not able to remove the determined R-ROIs in the FI condition altogether (see the values in the left top corner of the panels–left foot zoomed on the right side to highlight the differences in the R-ROIs surfaces). The recorded blueprints with related previously manually marked clinical at-risk locations (i.e. callosities and sites of previous ulcers) are superimposed on the FI related images. Reprinted under a CC BY license, with permission from Bioengineering & Biomedicine Company Srl, Pescara, Italy, original copyright 2020.
Fig 6.
Box plot for descriptive statistics summarising R-ROIs’ characteristics.
Mean (circles) and Median (squares) and Max (diamonds) values are reported. All reported values are expressed in cm2.
Table 2.
Post-Hoc pairwise signed-ranks test for the comparison among considered conditions.
Table 3.
Mean pressure reduction in residual R-ROIs for FI vs custom-made insole comparison.