Hand performance changes under acute exposure to moderate and mild hypobaric hypoxia

Background: Hypoxia might have direct impacts on human functions, and leads work efficiency reduction. The study is to investigate the effects of acute exposure to moderate and mild hypobaric hypoxia on hand performance. Methods: Nine healthy subjects participated in this study, in which each subject was tested at ground level (as Control group) and at simulated altitudes (3500m, 4000m, 4500m, 5000m, and 5500m) in a hypobaric chamber. The test aiming at assessing hand performance is comprised of four objective tasks: ´Insert sticks in to holes-board´ (ISIHB), ´nut-bolt assembly task´ (NBAT), ´shape discrimination´ (SD), and ´Grip strength´ (GS), and one subjective task: ´questionnaire subjective sense´. Results: Accomplish time (AT) performance of ISIHB and NBAT was significantly less in experiment groups compared to Control group. Such reduction of AT was further increased at the altitudes of 5000m and 5500m. Reaction time (RT), RT performance and synthetical (correct reaction rate and RT, CR RT) performance of SD varied significantly in experiment groups. GS performance declined, but with no significant difference at all simulated altitudes. Fatigue performance and tolerance performance was also been found with no significant difference in experiment groups. Subjective Sense changed significantly only at 5000m and 5500m. Conclusion: Acute exposure to moderate and mild hypobaric hypoxia significantly reduces the hand performance. ISIHB, NBAT, SD and Subjective Sense are more sensitive to hypoxia in experiment group, in which their task performance significantly decreases at five simulated altitudes.