Comparison of Two Accelerometers for Assessment of Physical Activity in Preschool Children

Purpose
The primary aim of this study was to test the validity of two accelerometers, CSA/MTI WAM-7164 and Actiwatch, against direct observation of physical activity using the Children’s Physical Activity Form (CPAF).

Methods
CSA/MTI WAM-7164 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.

Results
For total physical activity, CSA/MTI output was significantly correlated with CPAF (r = 0.72, p < 0.001), but output from the Actiwatch was not (r = 0.16, p > 0.05).

Conclusions
In summary, the present study found that, for measurements of total engagement in activity, the CSA/MT1 WAM-7164 was more accurate than the Actiwatch when compared against direct observation of activity.