A study of the talocrural (ankle) and talocalcaneal (subtalar) joints was made in order to acquire as much information as possible on the exact locations of their axes of rotation . The material used was 46 cadaver legs which had the ligamentous and capsular structures intact. The study was limited to only one of the factors that influence joint motion:​ the shapes of the articulating surfaces.

With a specially designed apparatus, the two axes were determined in each specimen. Then a series of measurements was made of the angles between these two axes and between these axes and various lines of reference in the shank and foot . Measurements were also made to determine the location of the axis of the talocrural joint with respect to anatomic landmarks on the leg. Finally, the perpendicular distance between the two joint axes was measured, and, in an attempt to determine the location of the axis of the talocalcaneal joint by means of anatomic landmarks, a ratio was calculated between two segments of a line assumed to extend from the most lateral point of the lateral malleolus to the most medial point of the medial malleolus.

The measurements obtained from this sample indicate that the talocrural and talocalcaneal joints can be considered single-axis joints for purposes of bracing but that the variation in the positions of the different axes is such that they require individual determination . The use of certain skeletal landmarks to determine the axis of the talocrural joint appears to be feasible;​ however, no accurate method of determining the axis of the talocalcaneal joint in the living subject has emerged from this study. In addition, these data demonstrate the need to consider individual variations in any evaluation of disabilities of the ankle and foot.