This project is aiming at designing and validating insoles for flat/high-arched foot using OpenSim and other analyses. Many studies have reported that flat/high-arched foot can cause not only the short-term problems such as foot fatigue or ankle pain, but also long-term problems such as abnormal gait posture or knee/hip pain. Using various methods including OpenSim gait analysis, we are studying how gait patterns of patients with flat/high-arched foot are different from those of normal people, and how insole parameters affect users’ gait patterns.