I think you're experiencing (1) a combination of an inaccurate description ("move the wrist"), and (2) an incorrect interpretation of a slightly better description ("rotate the wrist").If I'm not mistaken, what is actually called for is best expressed as forearm rotation; the forearm is where the movement is initiated, and the wrist and hand rotate as a natural consequence.There needn't be (and almost certainly shouldn't be) any side-to-side movement of the wrist on the lateral plane.