title: Convergent validity of a piezoelectric pedometer and an omnidirectional accelerometer for measuring children's physical activity.
abstract: The aim of this study was to assess the convergent validity of a new piezoelectric pedometer and an omnidirectional accelerometer for assessing children's time spent in moderate to vigorous physical activity (MVPA).A total of 114 children (51 boys, 63 girls) aged 5-11 years wore a sealed NL-1000 piezoelectric pedometer (New Lifestyles Inc, Lee's Summit, MO) and an Actical accelerometer (Mini Mitter, Bend, OR) over one school day. The NL-1000 pedometers were randomized to one of two manual intensity thresholds used to define MVPA (1): Level 3 = 2.9 metabolic equivalent test (MET) and (2) Level 4 = 3.6 MET. Compared with the Actical, the NL-1000 underestimated the time spent in MVPA by 37% and 45% at intensity levels 3 and 4, respectively. In addition, the 95% limits of agreement were wide at both intensity levels (level 3 = -144%, 70%; level 4 = -135%, 45%), indicating a low level of precision.
authors: Centre for Physical Activity and Nutrition, Auckland University of Technology, Auckland, New Zealand.
authors: Scott
authors: S
authors: Duncan
authors: Kate
authors: K
authors: White
authors: Losi
authors: L
authors: Sa'ulilo
authors: Grant
authors: G
authors: Schofield
mesh_terms: D000054:Acceleration; D056044:Actigraphy / Q000295:instrumentation* / Q000379:methods; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D016001:Confidence Intervals; D005080:Exercise Test / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D015203:Reproducibility of Results