Scientific approach to the axis of rotation at the midtarsal joint.

Current biomechanical models of the midtarsal joint describe it as having two axes of rotation, the oblique and the longitudinal. The considerable freedom of movement available at the midtarsal joint means that kinematic assessment of its function and determination of its axis of rotation must be conducted under conditions that enable the joint to function as normally as possible. The assessments on which the concepts of the longitudinal and oblique axes are based do not meet this criterion. Understanding of the motions at the midtarsal joint will improve as techniques of kinematic assessment improve. Future descriptions of the midtarsal joint should adopt the standard terms applied to the other joints in the lower limb, which will facilitate the study of the midtarsal joint in relation to the function of the rest of the lower limb.