The present study was intended to examine the propriety of the measurement using two weighing machines from the viewpoint of the simple measurement of standing ability.
　In this report, 34 healthy adult men and 16 healthy adult women were employed as subjects. Two weighing machines were placed in parallel and subjects stood on these machines with each foot. First of all they maintained this posture at 30 seconds with closed eyes, so we can see their postal sway by one of the weighing machine. The result we have got by this measurement, we will call the maximum change (MC).
　To investigate the validity of this simple measurement method, we compared MC with results of a gravicorder. Besides we tested their physical fitness and took hold of their conditions of physical exercise in order to investigate some related factors to standing ability.
　The following results were obtained:
　1) MC showed the relation to the shaking length and area of the center of gravity. It was also related to the age.
　2) The placement of the center of gravity showed a significant relation to the back strength both on men and women.
　3) The subjects, who obtained high score in physical fitness tests, showed small increment of shaking in the center of gravity from the opened eyes condition to the closed eyes condition.
　4) In the untrained subjects, their placements of the center of gravity were placed backward.
　The mentioned findings suggested that the simple measurement of standing ability by using two weighing machines and a back strength dynamometer was appropriate. In addition, the physical exercise will have a good effect on standing ability. We thought it was necessary to study the mechanism of the physical exercise with effects on standing ability, further more.

DESCENTE SPORTS SCIENCE Vol.6/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE