Introduction: A theory is presented to explain the major findings regarding motion sickness and to synthetize current theories concerning its etiology. The theory proposes that an imbalance in the output of the two major organs of the labyrinth-favoring the semicircular canals over the otolith organs-is responsible for most instances of motion sickness as experienced in terrestrial and microgravity environments.
Methods: Strengths and limitations of current theories are first outlined before the different roles of the canals and otoliths in the genesis of motion sickness symptoms are described.
Results: The proposed theory is shown to explain a large number of findings and integrate current theories.
Discussion: The role of vestibular imbalance in motion sickness may be a consequence of the more general differences between the canals and otoliths in autonomic control.Previc FH. Intravestibular balance and motion sickness. Aerosp Med Hum Perform. 2018; 89(2):130-140.