2001 Volume 1 Pages 15-20
This study examined the relationship between the mean direction of the displacement of the center of pressure (COP) and physical and mental conditions. Thirteen males and two females aged 18 to 35 years without neuropathy participated in this study. The measurement of COP for 1 min was carried out 100 times over several months for each subject. The measurement instrument was an Anima's stabilometer G5500. Data were recorded every 20 msec. Before each measurement, a questionnaire regarding physical and mental fatigue, heart rate, sleeping hours, and specific physical and mental conditions or states were taken from each subject. The X and Y directions of the displacement of the COP were plotted in two-dimension coordinates for about 100 trials with each subject. The probable ellipses were calculated from the plotted data, and the trials out of the probable ellipses were judged as extraordinary trials. The relationship between heart rate and sleeping hours, and the displacement of the COP was low. However, trials where the displacement of COP departed from normal tended to be associated with a high feeling of fatigue. The tendency for the displacement of the COP from normal after exercise suggests that fatigue may influence posture control.
