Design and Development of Orthoptic Footwear for Individuals with Flat Feet

Flat foot, is a medical condition characterized by a flatter-than-normal medial longitudinal arch (MLA), causing the entire sole of the foot to make close or direct contact with the ground surface. Studies indicate a prevalence of flat foot in the adult population ranging from 13.6% to 26.62%, resulting in foot pain and a diminished quality of life. Orthotic shoes present one treatment method for flat feet. This research aims to analyze the correlation between the arch index and the rear angle of the foot in individuals with flat feet, as well as to design orthotic shoes and insoles. The methodology involved 5 female students with an arch index greater than 0.26, measured through digital sole prints, and the rear angle of the foot assessed using a goniometer. Insole molding design utilized Rhinoceros software and was 3D printed. The insoles were crafted from materials comprising 90% silicone rubber, 10% talc, and 4% hardener of the total. The results indicated that all subjects exhibited flat feet, as evidenced by a nonsignificant reduction in the eversion angle at the rear corner of the foot. In conclusion, there exists a correlation between the arch index and eversion angle in flat foot measurements. Additionally, orthotic shoes and insoles can be customized based on 3D scanning results, offering effective treatment and comfort for individuals with flat feet.