Evaluation of 2D joint kinematics during stance using markerless shank and foot segmentation, modelling and tracking

This study focuses on evaluating the 2D movement of the shank and foot complex during the stance phase of walking by using a markerless approach. Markerless techniques have been often proposed as the next alternative to marker-based approaches. When marker positioning and/or visibility are an issue, markerless techniques could be an appropriate choice. However, the computational and technical complexity of a full 3-D description of the kinematics of the entire human body slowed the introduction of markerless approaches in routine clinical gait analysis. In this study, to gradually face such complexity, the analysis was limited to the 2D kinematics of a specific compartment of the human body during gait. The appropriate choice of image processing techniques showed that a markerless approach could be successfully used when applied to limited portions of the human body and during favourable motor tasks. The quality of the information obtained with the markerless approach is comparable to that obtained with a traditional marker-based approach. In addition, in selected clinical issues, the proposed markerless approach could be a valid alternative to more expensive 3D motion capture systems.