Changes in Center of Gravity Sway Caused by Alcohol Intake

Abstract

As alcohol intake affects the central nervous system, it may increase the center of gravity sway. This study aimed to examine changes in the center of gravity sway after alcohol intake. The study included 11 young participants (5 males and 6 females). The center of gravity sway was measured twice before and four times after alcohol intake (15% of frequency, 0.54–1.83 mL per each participant’s weight). In addition, simultaneously, blood pressure, heart rate, whole-body reaction time, and one-leg standing time with eyes closed were measured before and after alcohol intake. Position changes in sway were examined using a 5 × 5 cross table (5 categories: A–E) based on the percentile rank values of standard deviations X and Y (dispersion variables), which were made up by of large-sample (population) data. After alcohol intake, the mean values of all variables, except for blood pressure, significantly changed. In addition, the means of the COP sway variables (standard deviations of X and Y, length per unit time, and rectangular area) significantly changed. Among the 11 participants, 5 participants showed changes in the 5 × 5 cross table from near center to the EE position. Hence, it was inferred that the position in the cross table changed with alcohol intake. However, as some participants showed minor position changes after intake, individual differences in the effects of the same amount of alcohol intake were considered to exist. In conclusion, dispersion variables were affected by alcohol intake, but personal change of the position in the cross table made up from large-sample data differed considerably across individuals.