A three-dimensional finite element model of the human ankle joint has been developed to study the mechanisms of impact injury to the major bones of the foot. The model is based on anatomically realistic bone geometry obtained from medical imaging and includes the major ligaments of the ankle. Careful consideration was given to model the soft tissues of the plantar surface of the foot. The model was used to simulate axial impulsive loading applied at the plantar surface of the foot. The stability of the ankle joint was achieved in the model strictly by the intrinsic anatomical geometry and the ligamenteous structure. The time history response of input/output accelerations and forces compared reasonably well with experimental data. Results indicate that the calcaneus experiences the highest stresses followed by the tibia and talus. This is in agreement with several experimental data on calcaneal fracture in axial dynamic loading. Also, the model gives stress localization in the lateral–collateral ligaments that agrees with injury observations for that region. The significance of the model lies in its potential uses as a research tool for understanding the mechanical response of the ankle related to injury and degenerative disease.
Keywords: Impact biomechanics; Finite elements; Orthopaedic