A Semi-Active Dynamic Rapid Evaluate and Adjust Device for Prescribing Custom Foot Orthoses

Abstract

Traditional custom foot orthoses (CFO) prescription methods often suffer from lengthy processing times, material waste due to refabrication, inconsistent performance due to inaccurate foot alignment, and inadequate consideration of soft tissue impedance. To address these issues, this study proposes a novel framework for CFO prescription that incorporates adjustable devices, dynamic testing, and subject feedback into the design cycle, thereby reducing delivery time. These shortcomings adversely affect the treatment of critical conditions such as foot ulcerations from diabetes, plantar fasciitis, foot deformity, and Achilles tendonitis. The Arch Height Evaluate and Adjust Device (AHEAD), designed for dynamic testing with the human-in-the-loop, was used to assess the performance of varying orthoses arch heights in different subjects. Plantar pressure measurements during gait and subjective feedback were utilized to determine optimal arch heights. Among ten subjects, the mean increase in medial midfoot peak pressure between the maximum comfortable orthoses arch height and the base profile was 37.57(±22.39) kPa, with an acceptable orthoses arch height range of 3.90(±1.26) mm. This framework offers a rapid, quantitative assessment of the relationship between orthotic design variables and dynamic performance, significantly reducing the time required for CFO prescription.