2-D Lower limb joint kinematics using a hybrid markerless approach applied to video camcorder acquisitions

A hybrid markerless technique is presented and applied to estimate the 2-D lower limb joint kinematics from acquisitions recorded using a video camcorder. The proposed methodology is defined as hybrid since it uses garments as “segmental markers”, specifically high-cut underwear which contributes in defining the pelvis segment and ankle socks for the definition of the foot segment. The method was applied to video sequences acquired with a video camcorder and was validated by using a stereophotogrammetric markerbased system. Results show that the proposed technique can be considered as an easy-to-configure and affordable alternative to marker-based photogrammetric systems.