Measuring human movement for biomechanical applications using markerless motion capture

Modern biomechanical and clinical applications require the accurate capture of normal and pathological humanmovement without the artifacts associated with standard marker-based motion capture techniques such as soft tissue
artifacts and the risk of artificial stimulus of taped-on or strapped-on markers. In this study, the need for new markerless
human motion capture methods is discussed in view of biomechanical applications. Three different approaches for
estimating human movement from multiple image sequences were explored. The first two approaches tracked a 3D
articulated model in 3D representations constructed from the image sequences, while the third approach tracked a 3D
articulated model in multiple 2D image planes. The three methods are systematically evaluated and results for real data
are presented. The role of choosing appropriate technical equipment and algorithms for accurate markerless motion
capture is critical. The implementation of this new methodology offers the promise for simple, time-efficient, and
potentially more meaningful assessments of human movement in research and clinical practice.