Examination of Intra-trial and intra-day reliability for the center of foot pressure in static standing posture of fourth grade primary school students.

Abstract

The purpose of this study was to examine intra-trial and intra-day reliability of measurement variables for the center of foot pressure (COFP) in static standing posture of fourth grade primary school students. The subjects were 14 boys and 16 girls who were fourth grade primary school students in Hyogo prefecture, Japan. Sixteen measurement variables of COFP were calculated using Gravicorder (GP-5000, ANIMA corporation). The measurement variables of COFP were calculated while they stood on the examining table for thirty seconds under open and closed eye conditions, measured three times with a minute rest between each measurement, and on a separate day once in the morning and once in the afternoon for each subject. The results indicated that intra-class correlation coefficients more than 0.7 for three times measurements were 5 variables under open eye condition and 8 variables under closed eye condition in 16 variables. Under open eye condition, six variables showed additive errors and nine variables showed proportional errors in the intra-day comparison.In conclusion, we suggest that it is reasonable to use the first trial as a representative value for the measurement of COFP, and intra-day reliability of measurement variables COFP under close eye condition were superior than under open eye condition in the fourth grade primary school students.