Static and dynamic optimisation of fluid-filled responsive orthotic insoles

Abstract

This study was focused on developing an optimisation-based methodology to create customised solid–liquid composite (SLC) orthotic insoles. The goal was to reduce peak plantar pressures through gait through a dynamic numerical optimisation. A gait simulation was developed through a series of numerical models with increasing complexity. These models were validated against experimental analyses. The insole was designed based on numerical optimisation techniques that regionally tailored the insole with the aim to reduce temporal peak pressures. A prototype of the optimised insole was created using additive manufacturing and tested experimentally. The numerical gait simulation showed good correlation with experimental results. The largest differences are attributed to the bone geometry adopted from a previous study from a subject of different age, gender and size demographics. The optimisation process showed significant reductions in peak plantar pressures in the static peak pressures by approximately 8% and in the summation of dynamic peak pressures by 50%. Experimental validation confirmed the numerical predictions, highlighting the effectiveness of the optimised insole. The findings suggest that the optimised insoles can improve plantar pressure distributions and reduce peak pressures, making them a viable alternative to traditional orthotic insoles. Future research should focus on more accurate geometry for the numerical models and clinical trials.