Current Pedorthics | July-August 2019 | Vol.51, Issue 4 | Page 45

Optimization of rocker sole footwear the 1st MTP region or the hallux region (Table 1), showing that the effect of varying apex position was the same irrespective of rocker angle. However, in the 2-4th MTH region, increasing apex position angle from 62% to 67% lead to an increase in pressure with the 15° but not the 20° rocker angle (Fig. 2h, Table 1). Nevertheless, at the more proximal apex positions (when there was lowest pressures), the effect of changing apex position was consistent across the two rocker angles (Fig. 2h). The apex position at 52% of shoe length was found to minimize peak pressures for the largest proportion of individuals for both rocker angles (Table 2). The one exception was in the hallux region with a 15° rocker angle in which the 57% apex was shown to be optimal. designs produced 30% and 37% reductions in peak pressure (for the RA = 15° and 20° respectively, Fig. 3). Given the consistency of the 52% apex position, this was selected as the group-optimized design for all anatomical regions and both rocker angles. Peak pressures were significantly higher in the control shoe compared to the group-optimized designs (Fig. 3, p < 0.001). This difference was most pronounced for the 2-4th MTH region, for which the two group-optimized There were only small differences in performance, between the group-optimized and personalized footwear, within the context of the 200 kPa threshold. For example, with a RA = 15°, the proportion of individuals with pressures <200 kPa was only 4–6% larger with the group-optimized design, compared to the personalized design. Similar trends were observed with the 20° rocker angle, however, interestingly, there was no increase in the proportion of participants beneath the 200 kPa threshold in the 2-4th MTH region (Table 3) with personalized footwear. Nevertheless, there was up to 12% increase in the proportion of individuals under the 200 kPa threshold when the group-optimized 15° rocker angle was compared to the group-optimized 20° rocker angle design (Table 3). Table 3 also illustrates the proportion of individuals with diabetes and peripheral neuropathy under the 200 kPa threshold. These data follow similar trends to those of the full cohort of people with diabetes, despite the fact that peak pressures (across all the eight rocker shoe designs) were between 6 and 9 kPa higher in the neuropathic (n = 17) compared to the nonneuropathic group (n = 85). Current Pedorthics | July/August 2019 43