Shank–foot complex 2-D kinematics during stance using markerless segmentation and body-segment anatomical axes identification

Shank and foot complex is considered to be a fundamental mechanism of the lower limb in locomotion [1]. Typically marker based techniques are used to analyze the shank and foot kinematics [2]. Three markers per segment are mounted. The disadvantages of this technique are the complexity stemming from the number of markers per segment and the interference of markers with the subject and the subject’s movement. In this work, a markerless approach, which uses the 2-D images acquired by a digital camera, is proposed. The shank-foot complex is defined as a three-segment model by applying image processing techniques to the images of a subject walking in both barefoot and socked conditions. The aims of the current technique can be summarized as: (1) to ease the process of data acquisition by eliminating the markers and including the possibility of wearing socks; (2) to track the shank–foot complex kinematics with a three-segmented model.