BioMotH department seminar

Hamilton, Lagrange and chaos: that hidden Mechanics behind our movements

Understanding the fundamental principles governing the motions observed in nature is a fundamental goal of science, both with regard to inanimate objects and living systems including humans.

After Newton's pioneering work, mechanics evolved considerably thanks to the reformulations of Lagrange and Hamilton. Invoking a principle of least action, Lagrange replaced Newton's equation, , by the search for a unique function, minimized by physical trajectories.

After Newton's pioneering work, mechanics evolved considerably through the reformulations of Lagrange and Hamilton.

By constructing the phase space, integrating all a system's degrees of freedom (positions and velocities), Hamilton enabled a geometrical approach to motion, which emphasizes not only the minimization of action, but also the search for invariant quantities.

As we travel through the various formulations of mechanics, we'll show that they offer tools for a better understanding of voluntary human movement. The principle of least action appears as the conceptual basis for planning a movement, while phase space offers a graphical representation of movement, its variability but also its invariants (White, 2025, doi: 10.3389/ams.2025.1692890).

After three years of post-doctoral research at UMons in the field of particle physics, he joined HELHa in September 2011 and now holds a position as Senior Lecturer.

In addition to his teaching activities, he is now developing projects at the interface between new technologies and issues related to physiotherapy.

His current research focuses mainly on the quantification of human movement and the corresponding signal analysis techniques.