Customized Foot Orthoses Improve the Dynamic Plantar Loading in Painful Pes Cavus Subjects – New Analysis of a Blinded, Randomized Trial

The purpose of this study was to evaluate the benefit of customized foot orthoses (CFO) in improving dynamics of plantar loading quantified using the Regression Factor (RF) Index. RF index represents the similarity of the statistical distribution of the plantar pressure during stance phase with a Gaussian distribution. As the value increases positively so does the similarity between the pressure and Gaussian distributions. Plantar pressure data from 154 participants with painful Pes Cavus were retrospectively re-analyzed. The participants were randomized to an active treatment group given CFO or a control group given sham orthoses. In addition, plantar pressure data were collected on 20 healthy volunteers with no foot pain. Results demonstrated a significant improvement in the active treatment group compared with the control group. Interestingly, results suggest that CFO significantly improve the plantar pressure distribution quantified by RF index (p<0.005), while no difference was observed in the control group (p>0.9). Additionally, the RF index showed that the healthy participants’ dynamic pressure distribution was significantly closer to a Gaussian than participants with painful Pes Cavus. This study suggests that painful Pes Cavus alters the distribution of plantar loading during walking and CFO as an effective therapeutic solution can significantly improve it.