Abstract
Anxiety is defined as an over-arousal state, and anxious patients complain of a variety of physical symptoms. Concerning the maintenance of balance, a correlation between anxiety and postural instability is suspected. Therefore, we examined whether anxiety correlates the parameters of balance control in healthy college students employing a within-subject paradigm. State anxiety and body sway were measured twice with an interval of a month. Anxiety was scored by Spielberger's state-trate anxiety inventory just before the experiment. Body sway of each participant was then recorded for first with eyes open and next with eyes closed. Correlations between the changes in state anxiety and parameters of body sway were examined by Pearson's correlation analysis. Changes in enveloped area of body sway (ENV) and in maximum length of the antero-posterior body sway (YML) showed positive correlation with changes in state anxiety (ENV: r=0.534, p=0.013; YML: r=0.659, p=0.001). Data showed that an increase in anxiety caused an instability in the control of postural balance. These correlations were abolished when the eyes were closed. In conclusion, an increase in state anxiety caused an instability of postural balance in antero-posterior axis and increased the area of body sway. A possibility is raised that state anxiety affects the processing of visual inputs and influences the net performance of the postural control. [Jpn J Physiol 54 Suppl:S241 (2004)]
