This study examined the perturbing influence of deep breathing on the magnitude and direction of the displacement of the center of pressure (COP) during static standing with subjects breathing quietly. Five males and five females who have no neuropathy participated in this study. Platform stabilometry during 1 min in the upright posture with Romberg (open eyes and closed feet) was carried out 3 times with 1 min rest in between. The measurement instrument was Anima's stabilometer G5500. Data were recorded every 20 msec. The two parameters regarding the magnitude and direction of COP were: the mean of absolute values of COP (MABC) and the mean of values (MACC) along the lateral axes (COPX) and anterior-posterior axes (COPY) during 15 sec before (Pre-DB) and after (Post-DB) deep breathing. There were no significant differences in MABC for both COPX and COPY between Pre-DB and Post-DB. The MACC of COPY tended to change between Pre-DB and Post DB. In addition, 80% of the males moved forward, while 80% of the females moved backward after deep breathing. It is suggested that there was little perturbing influence associated with deep breathing for COP, but the mean direction of COP for individuals moved forward or backward.
