Influence of insole slope on bone joint stress, foot bone stress, and foot pressure distribution

Abstract

This study aimed to investigate the effect of insole slope on bone joint stress, foot bone stress, and foot pressure distribution by means of finite element (FE) methods. A three-dimensional (3D) FE model was reconstructed from computed tomography data using image processing and computer aided design software. A model of an insole placed under the foot skin in 3D FE model geometry was based on a Smile Feet insole. Four conditions for the analysis included one barefoot biomechanical analysis and three biomechanical analyses with 0-, 5-, and 10-degree insole slopes. In the barefoot analysis, high foot pressure was concentrated on the forefoot and heel regions. The insole redistributed the foot pressure to the mid-foot region and reduced stress at the intervertebral discs of L4-L5 and L5-S1, and at the hip joint. The slope of the in-sole resulted in changes in the stress exhibited in various joints and bones. Higher insole slopes tended to increase the stress, especially at the ankle joint and foot bones.

Keywords

• insole slope
• bone stress
• joint stress
• foot pressure