The effect of posture on reaction time with respect to age and gender

[Purpose] We examined the influence of age and sex on the simple reaction time, the vocal response to an auditory signal, in sitting, standing and supine. [Subjects] The subjects were 34 young persons and 65 elderly persons. [Method] Measurements of the response timer were performed in sitting, standing and supine. The measurement times were 3 for the young subjects, and 4 for the elderly subjects. Then we performed a comparative study of the subjects in each position by age and gender. [Results] Among the 3 positions, significant differences in the reaction times were not found among young and elderly males and young females. Among elderly females, the response time was significantly prolonged in supine compared to sitting and standing. In the comparisons of each gender, the reaction times of elderly males were significantly prolonged compared to that of young males in supine. In the comparisons of each age group, young females had significantly prolonged reaction times compared to young males in all of the three positions. [Conclusion] The reaction times of the elderly females were prolonged in supine, compared to sitting and standing, suggesting the involvement of arousal. We consider further investigations involving activity status are required.