Coordinated locomotion requires matching efferent commands (e.g., to one’s limbs) against afferent visual ªow information and vestibular and somatosensory (skin, muscle, and joint) signals concerning changing forces on one’s body (Guedry, 1992). If accurate afferent information about forces related to one’s own movement was suddenly absent during walking, running, carrying, reaching, climbing, etc., one would fall over. Nevertheless, simulation-corroborating acceleration/motion cues are seldom available to users of simulators or virtual environments (VEs) moving through a simulated world, a situation that contributes to incoordination, imbalance, cybersickness, and simulator aftereffects. Even VE users riding passively in simulated automobiles or aircraft are forced to control the simulated vehicle via visual ªow alone, without being able to match visual ªow information to the (actual and expected) afferent information about the forces on their own bodies, as they do during real acceleration, deceleration, and turning in vehicles. Consequently, the virtual experience causes unwanted symptoms and fails to be realistic.