Abstract
The purpose of this study was to investigate the validation of a physical activity assessment method using wrist-worn equipment (Microstone Inc. model ViM ver.2.1.0) in 27 healthy young male subjects. The protocol of this experiment was 9 min. of sitting at rest followed by walking or runnig free-style on a treadmill at a speed of 2.4 km/hr increasing to 3.6, 4.8, 6.0, 7.2 km/hr every 3 min. with no rest. Energy expenditure was compared among an expiratory gas analytical instrument (Minato Medical Science Study, Inc. model AE-280), the wrist-worn accelerometer and a hip-worn accelerometer (Suzuken Inc. model Lifecorder). There were significant correlations between energy expenditure measured by the expiratory gas analytical instrument and the wrist-worn accelerometer (r=0.84, p<0.01), and the hip-worn accelerometer (r=0.92, p<0.01). In a Bland-Altman-plot, the graphs of both the wrist-worn accelerometer and the hip-worn accelerometer vs. expiratory gas analysis were distributed over a range that was approximately equal. Both the wrist-worn accelerometer and the hip-wearing accelerometer are useful for measuring physical activity in elderly persons, and we may use them according to differencs in ability for measuring physical activity.
