[1] Institute for Medical Engineering and Information Processing (MTI Mittelrhein), University Koblenz-Landau, Koblenz, Germany
[2] Mechanical Systems Engineering, Swiss Federal Laboratories for Materials Science and Technology (EMPA), Duebendorf, Switzerland
[3] Department of Mathematics and Natural Sciences, Institute of Sports Science, University Koblenz-Landau, Koblenz, Germany
[4] Department of Mathematics and Natural Sciences, Mathematical Institute, UniversityKoblenz-Landau, Koblenz, Germany
[5] Department of Neurosurgery, University Medical Centre, Johannes Gutenberg-University Mainz, Mainz, Germany
[6] Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh,PA, United States