APBS provides force calculations for both polar and nonpolar solvation following the same procedures used in the "How do I calculate a solvation energy?" section. In general, forces can be obtained by modifying input files used for solvation energy calculations to include calcforce total (for total forces on the entire solute) or calcforce comps to obtain detailed force information for each atom.  See the polar calcforce and apolar calcforce documentation.  For polar solvation forces, it is important to note that, like solvation energy calculations, "self-interaction" terms must be removed.