  The equatorial motion of extended bodies in a Kerr spacetime is investigated
in the framework of the Mathisson-Papapetrou-Dixon model, including the full
set of effective components of the quadrupole tensor. The numerical integration
of the associated equations shows the specific role of the mass and current
quadrupole moment components. While most of the literature on this topic is
limited to spin-induced (purely electric) quadrupole tensor, the present
analysis highlights the effect of a completely general quadrupole tensor on the
dynamics. The contribution of the magnetic-type components is indeed related to
a number of interesting features, e.g., enhanced inward/outward spiraling
behavior of the orbit and spin-flip-like effects, which may have observational
counterparts. Finally, the validity limit of the Mathisson-Papapetrou-Dixon
model is also discussed through explicit examples.

General Relativity and Quantum Cosmology