Abstract
[Purpose] The purpose of this study was to clarify the validity of postural sway measurements in the static standing position made by accelerometers placed on different body segments. [Subjects and Methods] The subjects were 21 healthy adult males. Center of pressure (COP) on a force plate and acceleration measurements were made under four conditions: with the subjects' eyes open and closed, and on hard and soft surfaces. The root mean square (RMS) value of the acceleration of the head, the 4th thoracic vertebra and the 5th lumbar vertebra were calculated and the differences between each condition were analyzed. [Results] On the soft surface, the acceleration of each body segment showed differences between the conditions similar to COP. [Conclusion] The measurement of the acceleration RMS of each body segment on a soft surface may be a useful new evaluation index, in place of the conventional COP path length measurement.
