Visualization of the Motion of the Human Spine in the Context of Gait Analysis through Splines

The present paper describes an approach for the reconstruction of the motion of the human spine based on marker tracking. The approach uses a spline curve of fifth degree to reproduce the contour of the central marrow line and a set of virtual sliders along the spline with fixed offset distances which model external markers including skin motion. The fitting process is formulated as an optimization problem minimizing the quadratic error between the tips of the sliders and the measured marker positions. The paper also discusses some simplifications of this approach. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)