Chasing feet in the wild: A proposed egocentric motion-aware gait assessment tool

Despite advances in gait analysis tools, including optical motion capture and wireless electrophysiology, our understanding of human mobility is largely limited to controlled conditions in a clinic and/or laboratory. In order to examine human mobility under natural conditions, or the 'wild', this paper presents a novel markerless model to obtain gait patterns by localizing feet in the egocentric video data. Based on a belt-mounted camera feed, the proposed hybrid FootChaser model consists of: 1) the FootRegionProposer, a ConvNet that proposes regions with high probability of containing feet in RGB frames (global appearance of feet), and 2) LocomoNet, which is sensitive to the periodic gait patterns, and further examines the temporal content in the stacks of optical low corresponding to the proposed region. The LocomoNet signicantly boosted the overall model's result by ltering out the false positives proposed by the FootRegionProposer. This work advances our long-term objective to develop novel markerless models to extract spatiotemporal gait parameters, particularly step width, to complement existing inertial measurement unit (IMU) based methods.