Motion Sickness Provoked by Torso Rotation Predicts That Caused by Head Nodding

Cloutier A, Watt DGD. Motion sickness provoked by torso rotation predicts that caused by head nodding. Aviat Space Environ Med 2006; 77:909–914.



Introduction: Some degree of space motion sickness is experienced by at least 50% of astronauts early in flight. It is unpleasant and could be hazardous during an extravehicular activity or urgent re-entry in the first few days after launch. To date, there is no reliable ground-based test to predict who will be affected. Methods: Head nodding (HN) in a supine position was used as a model of motion sickness caused by an unusual gravito-inertial environment. Torso rotation (TR) was used as a means of predicting susceptibility to development of symptoms caused by HN. Motion sickness was quantified in 26 subjects (5 men, 21 women, age range 18–52) using numerical estimates of discomfort and a more detailed questionnaire. Susceptibility to TR and HN was determined on three occasions for each stimulus, with test sessions at least 1 mo apart. Results: Subjects reached their stopping point at a mean duration of 13.72 min (± 1.06 CI) for TR and 11.31 min (± 0.38 CI) for HN. When susceptibility to HN was plotted as a function of susceptibility to TR and a linear regression line was added, the correlation coefficient was 0.744. Discussion: Susceptibility to TR predicts susceptibility to HN. The method may be useful as a screening test for potential astronauts.