BACKGROUND: In recent years, with the wide application of finite element analysis in the field of biomechanics, studies on the ankle joint from domestic and abroad scholars have been increased. However, the study is mainly on static states, searching the literature of the past few years, reports about ankle injury in non-mid-stance have seldom been found.
OBJECTIVE: To make finite element biomechanical analysis of the ankle three-dimensional digital model; to observe the changes of displacement distribution, shear stress and stress of every part of the ankle joint from different perspective; and to discuss the ankle injury mechanism under the condition of inversion.
METHODS: The three-dimensional digital model of ankle that processed in Mimics and Geomagic surfale was imported into Ansys, and then made a finite element analysis of the obtained model at different inversion angles after constraining conditions, loading pressure and solving.
RESULTS AND CONCLUSION: In this article ,10 different inversion angles of the ankle joint model were simulated successfully, that were 10°, 15°, 20°, 25°, 30°, 45°, 60°, 70°, 80° and 85°. At each inversion angle, we made finite element mechanical analysis, and obtained the distribution of displacement, shear stress, and stress of every part of the ankle joint from different spatial dimensional. After studying the datum, we draw a conclusion that the x (y, z)-displacement, xy (yz, xz)-shear stress, x (y, z)-stress were increased gradually with the increasing of the inversion angle, the maximum stress located on the lateral malleolus and the lateral part of trochlea tali, where was the most fragile part of the ankle joint to be broken. In addition, the x-displacement of talus was increased with the increasing of inversion angle, which influenced the distribution of stress on the whole ankle joint model.