Effect of Custom-designed Insole with Arch and Metatarsal Support on Adjustment of the Lower Limb Kinematics

Insole construction is considered to be related to stability in sports, and custom-made insoles with their scientifically tailored approach and effective construction are considered to be the main means of adjusting posture and reducing risk in sports. We have designed a non-100% full-fit design insole (CDI) with an arch support insole and metatarsal liner to determine whether this insole can be adapted to lower limb kinematics. Eleven healthy volunteers participated in this randomized crossover test in which a motion capture and 3D gait analysis system was used to measure the subjects’ lower limb kinematic data while exercising at different slopes and speeds wearing three different insoles: CDI, control Insole (CI) and arch support insoles (ASI). In addition, the experiments introduced the speed and slope factor, analyzed the extent to which speed slope affects joint angle using UNIANOVA, and compared the performance differences between the three insoles in different planes in pairs. The CDI inhibited ankle dorsiflexion and knee flexion in the sagittal plane; in the frontal plane, CDI reduced knee adduction and hip abduction angles. There was a statistically significant difference (p < 0.05) between the change in joint angle and the velocity slope. Slope*speed had a greater effect on the ankle and knee joints (%sig>30%). The results show that the CDI has better kinematic adjustability in the ankle and knee joints due to its superior insole design approach. Therefore, wearing the CDI may be an effective way of reducing risks in sports.