Fig. 3
Three-dimensional kinematics of the cadaver foot mobilized by a robotic simulator. a) Biplanar X-ray fluoroscopic images and corresponding registration results. Calcaneus, talus, navicular and cuboid at just before heel-contact, foot flat and just before toe-off are presented. b, c) The 3D movements of the tarsal bones are displayed in sagittal and anterior views, respectively. After heel contact, the cuboid and calcaneus are observed to move laterally away from the navicular. The articular surface of the cubocalcaneal joint is closely matched during the foot-flat. d) Tri-axial rotational angles of the calcaneus with respect to the talus. Angles are defined as zero at the time of heel-contact. Positive angles represent abduction, eversion, and plantarflexion of the subtalar joint