Design and Experimentation of a 3D Ankle Joint Goniometer

摘要

This paper presents a method for the human ankle joint kinematic measurement by using a mechanical linkage having 6 d.o.f., all equipped with position sensors. The device allows a complete identification of all kinematic parameters of the joint which can be expressed here in the form of the Instantaneous Helical Axis and gait portraits for 3 principal rotations of the joint; dorsi/planta flexion, pronation/supination and internal/external rotation. A symmetry study of the 2 ankles during walking was also realized which highlighted the asymmetrical nature of the human gait as the FFT analysis gives a significant difference in amplitude between the rotational velocity vectors of the 2 ankle joints.