[Changes in postural control mechanism after a long-time tilt].

In order to investigate the time-dependent dynamics of otolith organ-spinomotor function, we analyzed postural control biomechanically, in eight healthy adult volunteers, using a dynamic posturography (EquiTest System), before and after a four-hours lateral head and body tilt (90 degrees). After the tilt, a half of the subjects exhibited some changes. Their equilibrium scores decreased; i.e., the dependence on their vestibular inputs decreased, but in contrast, those on the visual and the somatosensory inputs increased. These changes were diminished by repeating the tests along the time course. The present findings confirmed [correction of comfirmed] the importance of vestibular gravity information for the maintenance of delicate postural stability.