Motion sickness: effect of the magnitude of roll and pitch oscillation.

BACKGROUND

Rotational oscillation in roll and pitch can cause motion sickness, but it is not known how sickness depends on the magnitude of rotational oscillation or whether there is a difference between the two axes of motion.

HYPOTHESIS: It was hypothesized that motion sickness would increase similarly with increasing magnitudes of roll and pitch oscillation.

METHOD: There were 120 subjects (6 groups of 20 subjects) who were exposed to 30 min of 0.2-Hz sinusoidal roll or pitch oscillation at 1 of 3 magnitudes: 1) +/- 1.830; 2) +/- 3.66 degrees; or 3) +/- 7.32 degrees. Subjects sitting in a closed cabin with their eyes open gave ratings of their illness on a 7-point illness rating scale at 1-min intervals.

RESULTS

Over the six conditions, mild nausea was reported by 17.5% of subjects. With both roll oscillation and pitch oscillation, mean illness ratings were least with +/- 1.83 degrees of rotational oscillation and greater with +/- 3.66 degrees and +/- 7.32 degrees of oscillation. At none of the three magnitudes of oscillation was there a significant difference in motion sickness caused by roll and pitch oscillation.

CONCLUSIONS

With rotational oscillation about an Earth-horizontal axis, there is a trend for motion sickness to increase with increasing motion magnitude. For the conditions investigated, similar motion sickness was caused by roll and pitch oscillation.