Comparison of the immediate effects of prefabricated soft medical insoles and custom-molded rigid medical insoles on plantar pressure distribution in athletes with flexible flatfoot: a prospective study

Abstract

Background: The aims of this quasi-experimental study were to compare the effect of prefabricated soft medical insoles and custom-molded rigid medical insoles on plantar pressure distribution in athletes with flexible flatfoot. Methods: Eighteen amateur athletes with flexible flatfoot participated in this study. All participants received custom-molded rigid medical insoles and prefabricated soft medical insoles. Mean peak pressure (kPa), maximum force (N), and contact area (cm2) were calculated for the heel, medial and lateral midfoot, first metatarsal head, second and third metatarsal heads, fourth and fifth metatarsal heads, hallux, and other toe area using the Pedar-X system (Novel GmbH, Munich, Germany) immediately. Results: The use of both prefabricated and custom-molded insoles significantly reduced the mean pressure and force in the heel, second and third metatarsophalangeal joints (MTP2,3), the fourth and fifth metatarsophalangeal joints (MTP4,5), and increased the pressure in the medial midfoot compared to the shoe (P<0.001). No significant difference was observed between the two insoles (P>0.05). The contact area increased significantly in the medial midfoot (P<0.001) and MTP2,3 (P=0.02) and decreased in the hallux (P<0.001) and other toes (P=0.01) using both insoles compared to only shoes. Conclusions: The results showed that the use of a medical insole in athletes with flexible flatfoot could alter athletics’ plantar pressures immediately. Since both insoles had a similar effect on the distribution of plantar pressures, it seems that the prefabricated soft medical insole is a more suitable option for daily use in athletes to prevent injury because of its availability and cost-effectiveness. Level of Evidence: Level II.