Passive motion characteristics of the talocrural and the subtalar joint by dual Euler angles.

The objective of this study is to validate previous descriptions of hindfoot kinematics using dual Euler angle methods in a passive cadaveric model. The dual Euler angle method was chosen so as to facilitate description of the translational and rotational movement occurring at both the ankle and subtalar joints. A non-metal experimental set-up was fabricated to generate motion in foot cadaver specimens. Three-dimensional kinematic data of the ankle joint complex was collected from ten knee-below foot cadaver specimens using a 'Flock of Birds' electromagnetic tracking device. The data correlates well with previously published kinematic descriptions of the ankle subtalar joint complex. Both the ankle and subtalar joint show 6 degree of freedom motion and multiaxial characteristics. The motions of the talocrural joint, the talocalcaneal joint, and the gross motion between the foot and the shank were analyzed. During dorsiflexion-plantarflexion the motion of the calcaneus with respect to the tibia occurs mainly at the ankle joint, with little motion at the subtalar joint. The subtalar joint contributes more than the ankle joint during inversion-eversion.