Association between the ability of maintain standing posture and whole-body reaction time in Japanese preschool children

Abstract

Objective：The purpose of this study was to examine the reliability of the measurement values of whole-body reaction time, and the association between the measurement values for the center of pressure （COP） in static standing posture and the measurement values of whole-body reaction time in Japanese preschool children. Methods： Subjects were 138 preschool children （70 boys, 68 girls）aged 5 to 6 who were enrolled in two kindergartens in Osaka prefecture. The measurement values of whole-body reaction time calculated using a T.K.K. 5408 （Takei Corporation, Niigata）. The measurement values of COP estimated Total Locus Length （LNG） and Environment Area （Env. Area） measured while children stood closed foot for 30 seconds under eyes-open and eyes-closed conditions using Gravicorder GS-7 （ANIMA Corporation, Tokyo）. Results：Intra-class correlation coeffi cients （ICC） for whole-body reaction time measurement values were above 0.7 for 5-year-olds of both sexes and 6-year-old boys. Signifi cant correlations were found between the measurement values of the environment area with eyes closed and the measurement values of whole-body reaction time in both 6-year-old boys and girls （boys: r=0.350, p=0.020; girls: r=0.378, p=0.013）. Conclusion：The average values of whole-body reaction time calculated in three trials, excluding the maximum and minimum of fi ve trials, demonstrated the statistical reliability of this study. We suggested that maintaining standing posture develops both vestibular and somatosensory sensations, which are stronger than visual sensation, and an association between the coordination of voluntary movements in 6-year-old boys and girls.