Design of a single computational model to simulate the three foot-rocker mechanisms of the gait cycle

Abstract

<title>Abstract</title> The use of computational models of the human foot based on finite element analysis (FEM) offers a promising avenue for understanding the biomechanical internal changes of this structure. Bone and soft tissues have been modeled. However, models reported in the literature often lack a comprehensive representation of the foot's dynamic. This research aims to overcome these limitations by designing a computational model that accurately simulates foot biomechanics during the stance period of the gait in healthy and flatfoot scenarios. The model is focused on analyzing stress variations in soft tissues such as the plantar fascia and spring ligament to provide valuable insights into the internal biomechanics of the foot. The designed FEM foot model includes 26 bones with cortical and trabecular differences, cartilages, ligaments, plantar fascia, and tendons related to foot arch support. The results were evaluated through maximum principal stress, and validations were performed by measuring clinical angles and compared with the range of motion for foot joints. Results show that the plantar fascia and spring ligament suffer a stress increment during mid-stance and toe-off compared to heel-strike. Additionally, as was expected, flatfoot simulations show stress increments in evaluated soft tissues, while surgical treatment scenarios contributed to tension reduction in these regions. The findings emphasize the active role of the plantar fascia and spring ligament, particularly during approximately 50\% of the stance period when the plantar arch is deformed. Results show valuable insights into the internal biomechanics of the foot through computational models.