The Influence of Prolonged High Altitude Deployment on Psychomotor Functions Among Chinese Military Plateau Motor Vehicle Operators: Does Deployment Duration Matter?

Abstract

Background:Psychomotor functions are necessary for Chinese military plateau motor vehicle operators (PMVOs) to complete their driving tasks. This study aimed to investigate (1) the influence of chronic exposure to high altitude (HA) on psychomotor functions among PMVOs; (2) whether deployment duration at HA moderated the effect of HA.Methods: 196 male PMVOs in Golmud (average altitude: 2,890 m) and 192 male lowland motor vehicle operators (LMVOs) were recruited as the studygroup (HA group) and control group (LA group). Both groups were in turn categorized into 3 groups by deployment duration: Group A (less than 1 year), Group B (between 1 year and 2 years), and Group C (more than 2 years). All participants completed simple reaction time, bimanual coordination test, fine motor dexterity test, and eye-hand coordination test. Between-altitude and deployment duration differences were explored usinganalysis of variance (ANOVA).Results: HA group participants had slower simple reaction time in comparison to LA group (F(1, 387) = 18.041, p< 0.001, ηp2 = 0.045).HA group needed less time to complete the bimanual coordination test (F(1, 387) = 2295.648, p< 0.001, ηp2 = 0.857). HA group had more error times in fine motor dexterity test (F(1, 387) = 5.980, p = 0.015, ηp2 = 0.015). HA group participants had better left aim index (F(1, 387) = 13.205, p< 0.001, ηp2 = 0.033) and more right hits (F(1, 387) = 3.916, p = 0.049, ηp2 = 0.010) in aiming test. The interaction effect of altitude and duration was significant on hit number with left hand in the tapping test (F(2, 387) = 3.327, p = 0.037, ηp2 = 0.017). Butsimple effect analysis showed that the effect of duration was not significant among HA group (p = 0.129).Conclusions: In this study, we found that prolonged exposure to HA may cause psychomotor slowing and declining fine motor dexterity. But, the moderating effect of deployment duration was not supported by this study.