Analytical expressions relating the trajectories of spherical nanoparticles pushed by an atomic force microscope tip to the scan pattern of the tip are derived. In the case of a raster scan path, the particles are deflected in a direction defined by the geometries of tip and particles and the spacing b between consecutive scan lines. In the case of a zigzag scan path, the particles are deflected in a range of directions around 90 degrees, also depending on the parameter b. Experimental results on gold nanoparticles manipulated on silicon surfaces in ambient conditions confirm the predictions of our model.