The use of pedometer and actometer in studying daily physical activity in man. Part II: validity of pedometer and actometer measuring the daily physical activity.

The validity of the pedometer and actometer for estimating the daily physical activity was evaluated by means of an observation study. The physical activity in a classroom of 11 pupils of a kindergarten was assessed by means of a pedometer, actometer and by observation. Besides this an activity questionnaire was completed by the infant-quide. On basis of the individual observation it is clear that the infant-guide can give valuable information about the activity of the children at school. The results of the pedometer attached to the waist and the actometers attached to the ankle were significantly correlated with the results of the observation method. The wrist actometer showed a smaller but still significant correlation with the other variables. Implications of this findings are discussed in regard toward the physical activity. The pedometer results point out that when the percentage of intense activity is high the pedometer tends to underestimate the level of activity. The actometer results indicate that such a motion recorder gives a reliable estimation of activity in children. The findings are discussed in terms of the practical applications of the actometer in the research of daily physical activity and the physical rehabilitation treatment of certain diseases.