Comparison of two accelerometers for assessment of physical activity in preschool children

The primary aim of this study was to test the validity of two accelerometers, CSAIMTI WAM-7164 and Actimatch(R), against direct observation of physical activity using the Children's Physical Activity Form (CPAF). CSA/MTI WAM7164 and Actiwatch accelerometers simultaneously measured activity during structured-play classes in 3- to 4-year-olds. Accelerometry output was synchronized to CPAF assessments of physical activity in 78 children. Rank order correlations between accelerometry and direct observation evaluated the ability of the accelerometers to assess total physical activity. Within-child minute-to-minute correlations were calculated between accelerometry output and direct observation. For total physical activity, CSA/MTI output was significantly correlated with CPAF (r =.72, p <.001), but output from the Actimatch was not (r =.16, p >.05).