TY - EJOU AU - Alexander, Eugene J. AU - Bregler, Christoph AU - Andriacchi, Thomas P. TI - Non-Rigid Modeling of Body Segments for Improved Skeletal Motion Estimation T2 - Computer Modeling in Engineering \& Sciences PY - 2003 VL - 4 IS - 3&4 SN - 1526-1506 AB - A necessary requirement for many musculoskeletal modeling tasks is an estimation of skeletal motion from observations of the surface of a body segment. The skeletal motion may be used directly for inverse kinematic calculations or as an observation sequence for forward dynamic simulations. This paper describes a fundamentally new approach to human motion capture for biomechanical analysis. Techniques for generating three-dimensional models of human skeletal elements from magnetic resonance imaging data are described, along with a methodology for corresponding these high-resolution internal models to externally observable features. A system for generating dynamic visualizations of these skeletal models from retro-reflective, skin-mounted marker motion capture data is also developed. Next, a set of techniques for estimating body segment shape and pose without the need for retro-reflective markers, from single and multiple, calibrated and un-calibrated cameras is developed. Example results from both synthetic and actual data sequences are presented. KW - DO - 10.3970/cmes.2003.004.351