A microanalysis of ethanol-induced disruption of body sway and psychomotor performance in women.

Measures of body sway, psychomotor performance and subjective reports of intoxication were obtained from 20 women after consuming either ethanol (0.56 g/kg) or placebo. Simple motor tasks were unaffected by the relatively low ethanol dose. Performance on the Digit Symbol Substitution Test (DSST) was affected only during the ascending portion of the blood ethanol curve while stance stability was disrupted during peak and descending blood ethanol levels. A microanalysis of the dynamic changes of ethanol-induced body sway was conducted and the results plotted in three-dimensional space. These data revealed that disruption of stance stability was more pronounced in the sagittal plane than in the lateral plane and that subjects swayed to the rear and the right side. The results of this study suggest that such data analysis techniques provide extremely sensitive measures of body sway resulting from consuming a moderate dose of ethanol.