Stylo-Handifact is a novel spatial user interface consisting of a haptic device (i. e., Stylo) attached to the forearm and a visualization of a virtual hand (i. e., Handifact), which in combination provide visuo-haptic feedback for posture training applications. In this paper we evaluate the mutual effects of Handifact and Stylo on visuo-haptic sensations in a psychophysical experiment. The results show that a visual stimulus can modulate the perceived strength of a haptic stimulus by more than 5\%. A wrist docking task indicates that Stylo-Handifact results in improved task completion time as compared to a state-of-the-art technique.