  We study theoretically the dynamics of a Shiba state forming around
precessing classical spin in an s-wave superconductor. Utilizing a rotating
wave description for the precessing magnetic impurity, we find the resulting
Shiba bound state quasi-energy and the spatial extension of the Shiba
wavefunction. We show that such a precession pertains to dc charge and spin
currents flowing through a normal STM tip tunnel coupled to the superconductor
in the vicinity of the impurity. We calculate these currents and find that they
strongly depend on the magnetic impurity precession frequency, precession
angle, and on the position of the Shiba energy level in the superconducting
gap. The resulting charge current is found to be proportional to the difference
between the electron and hole wavefunctions of the Shiba state, being a direct
measure for such an asymmetry. By dynamically driving the impurity one can
infer the spin dependence of the Shiba states in the absence of a
spin-polarized STM tip
