Nowadays, backache risks due to professional activities remain high, while their
quantitative estimation is not well-known. Different methods have been developed to
determine the exposure of the spinal column to risk of damage. In Belgium, the “Fond des
Maladies professionnelles” (FMP) suggests to use the “Mainz Dortmund Dosis” (MDD) method
to compute the exposure dose accumulated during the whole professional life. This method
uses the so-called biomechanical model “The Dortmunder” where the skeleton of the human
body is represented by 30 rigid bodies to which certain abdominal and back muscles are
linked. This paper presents an implementation of the Dortmunder model with EasyDyn, a
C++ library developed by the
Department of Theoretical Mechanics, Dynamics and Vibrations of the University of Mons for
solving multibody problems, among others. Our model is first validated by comparing the
obtained results with the one found in the literature. It is then used in a posture that
is not considered yet by the FMP. It is shown that working on ones knees can induce forces
in the back that increase the risk of backage.