Abstract
The purpose of this study was to know the function of mechanoreceptor in soles. Therefore, we cooled the soles at the temperature of -150℃ to make them less sensitive with a use of synthetic cryo-air transpire (Nippon Sanso Co., Ltd.). Then Hirasawa's cross-test was used when the subjects stood on the gravicoder to measure the center of pressure at the soles and the base of support. The duration time when the cold air was applied to the soles was classified in three conditions as follows : A) Not cooled as control, B) cooled for five minutes, and C) cooled for seven minutes.
The subjects were twenty healthy males. They were 19 to 29 years old with an average age of 21.4 years. Their mean height and weight were 171.6 cm and 64.5 kg, respectively.
The results were as follows : 1) With respect to the center of gravity in natural standing posture, the condition C) revealed the greatest backward displacement in fore-aft sway among all, then followed in order by conditions A) and B). 2) The sway area of condition C) was greater than other conditions and statistically significant. The distance of sway, however, revealed no significant differences among three conditions. 3) Cross-test in which the subjects could remain in standing posture in lateral movement revealed no significant differences among three conditions. However, the backward sway was significant in fore-aftward displacement.
Through these results, following two findings can be stated : 1) The pressure sensation might affect fore-aftward displacement. 2) The pressure sensation might participate in low frequent ingredient of postural control.
