Kinematic measurement of the ankle joint using a six d.o.f. electro-goniometer

This paper presents a novel design of a passive electro-goniometer for the kinematic measurement of human ankle joint. The device is a serial mechanical linkage having six degrees of freedom, all of which are equipped with optical encoders. When attached to the user's foot and leg, it allows the measurement of all spatial parameters of the relative movement between these two body segments. The kinematics of the ankle joint (particularly the planta/dorsi flexion, pronation/supination and internal/external axial rotation) can then be computed using these data. With this special design, the authors aim to provide an effective method for the assessment of the ankle joint's capacity of movement. The measurement method will be described in detail, and first experimental results will be presented and discussed as well.