ABSTRACT
<b>Objective</b> According to a survey conducted by the Japanese Ministry of Health, Labor and Welfare in 2002, 72% of workers feel fatigued, clearly indicating the degree to which the Japanese populace is affected by this problem. However, few scientifically proven anti-fatigue devices have been developed for the benefit of the Japanese society. An automated air massage chair provides soft stimulation with air bags, not spot stimulation with knead balls, over the muscle surface with movements that push the muscles upward. In the present study, using established methods to evaluate fatigue, we investigated the effect of this automated air massage chair on fatigue in healthy volunteers.<br> <b>Method</b> Ten healthy subjects participated in a randomized two-way crossover trial. As fatigue-inducing desk work, subjects performed 8 sets of a 30-min Uchida-Kraepelin psychodiagnostic test and 30-min advanced trail making test (ATMT) during the test day. Subjects rested 15 min on the air massage chair or control chair 4 times: immediately before and at 4, 6 and 8 hours after the start of the workload. We evaluated the subjective feeling of fatigue by visual analogue scale, work performance by ATMT, and analyzed underlying mechanisms by biochemical parameters in saliva and urine.<br> <b>Result</b> Stimulation by air massage chair alleviated the subjective sensation of fatigue and suppressed the decline in work performance. Furthermore, increase in salivary amylase activity and decrease in urine homovanillic acid/creatinine ratio was suppressed.<br> <b>Conclusion</b> Automated air massage chair attenuated fatigue induced by desk work, most likely by correcting the imbalance in the autonomic nervous system. The air massage chair is thus recommended for relieving fatigue induced by work and daily activities.<br>