Wearing socks does not affect markerless estimation of ankle and foot kinematics

Introduction: Traditionally, clinical gait analysis is performed asking the subject to walk barefoot. The rationale behind such requirement is that markers attached directly to the skin are expected to reflect more truthfully the underlying bone movement. Therefore, any layer of additional material over the skin may increase the chances of introducing artifacts. In markerless approaches, such requirement might not be the best choice. In fact, in 2D markerless techniques, a segment is defined by an area instead of a set of points and the presence of a layer over the skin can facilitate its identification. In this study we investigate the role of socks in determining joint kinematics using a markerless technique, compared to marker-based techniques.