2D video-based human gait analysis: A novel markerless approach

A 2-D markerless technique for the analysis of the lower limbs kinematics during gait is presented and preliminarily validated. Data were recorded using a single video camera placed laterally to the walkway. The preliminary validation was performed using a optoelectronic marker based system as gold standard. The lower limb facing the camera was modelled with four body segments: foot, shank, thigh and pelvis. Ankle socks and underwear garments were used as segmental markers to track the foot and the pelvis, respectively. The shank and thigh were tracked using multiple reference points defined in a calibration reference image. The comparison between the estimated segment angular kinematics and that obtained with the gold standard revealed a high correlation index and limited Root Mean Square Deviation (RMSD) values. The proposed technique can be considered as an easy-to-configure and affordable alternative to marker-based systems, for 2D human lower limb motion tracking during gait.