The measure of lower limb joint kinematics is helpful in evaluating gait alterations. Nowadays, optoelectronic stereophotogrammetry gait analysis is the gold-standard in clinical practice for quantitative assessment of human motion because it provides accurate results, but it is not without limitations. Video-based markerless (ML) systems can represent a promising alternative to 3D marker-based systems because it allows to make the experimental sessions faster and simpler because does not require the application of fixtures on the skin of the patients. In addition, recent advancements in depth camera (RGB-D) technology have paved the way to the development of a new generation of low-cost movement analysis systems.