Effects of Custom-made Insoles on Plantar Biomechanics and Upper Extremity Muscle Performance

OBJECTIVE To investigate the effectiveness of molding custom-made insoles for female patients with foot pain. METHODS The study included 20 patients whose insoles were prescribed according to biomechanical evaluations and molded by repositioning the subtalar joint in its neutral position using a simple set of tools. Plantar biomechanics were measured under the following conditions: static stand, walking at self-comfortable walking speed (CWS) barefoot, walking in patient owned running shoes, and walking in running shoes plus insoles. Each patient's upper arm isometric muscle strength and subjective feelings before and after the insole intervention were assessed. RESULTS The molded insoles increased plantar contact area both during static standing and walking at CWS compared to the barefoot condition. The insoles also had more evenly distributed plantar contact area and loading rate, with the changes in the medial arch area being most significant. Moreover, the custom-made insole intervention immediately increased maximum resistance and duration of bilateral upper arms, as well as improved foot comfort, especially at the medial arch area during single leg squat tests. CONCLUSION Molding custom-made insoles by repositioning the subtalar joint in its neutral position can be accomplished with a simple set of tools, making this method highly applicable for a majority of less developed regions. Insoles molded using this method are effective in immediately improving plantar biomechanics disorders and enhancing isometric upper muscle performance in female patients with foot pain.