Automatic determination of knee kinematics for lower limb rehabilitation manipulator design

This paper presents a fully automatic algorithm evaluating the knee joint kinematics on the basis of X-ray images. The practical instantaneous center of rotation (ICR) path acts as the main feature of interest. The X-ray images taken from unhealthy child subject while knee flexion, are used as an input data. A clear description of each step of the procedure is provided in the paper, i.e. the image preprocessing, morphological operations, object labeling, image stabilization, determination of bone landmarks, and calculation of ICR. The output information can be used as a basis in the design stage of lower limb rehabilitation manipulator.