title: Assessment of pedometer accuracy in capturing habitual types of physical activities in overweight and obese children.
abstract: Currently, there is a limited amount of research exploring physical activity measurement tools in overweight and obese (OW/OB) children using pedometers. Thus, our objective was to determine the accuracy of one spring-levered (SC-T2) and two piezoelectric pedometers (NL-1000 and Piezo) in OW/OB children.
  
  
  
  A total of 26 boys and 34 girls (n = 60) participated. Pedometer step-counts were compared to observed step counts for walking (walking, stair ascent and decent) and hopping tests. Pedometer accuracies were compared with Friedman tests while Bland-Altman plots were used to establish the accuracy of each pedometer against direct observations.
  
  
  
  Boys (n = 26) and females (n = 34) were 96 and 91% OB, respectively. The two piezoelectric pedometers (NL-1000 and Piezo) were accurate for walking and stair climbing tasks, however all pedometers were inaccurate for hopping tests. Averaged over all three walking activities, the NL-1000 was the most accurate with 6.7% median error (interquartile range (IQR): 0.0-13.3); followed by the Piezo with 10.0% median error (IQR: 3.3-18.1); SC-T2 was the least accurate with -14.7% median error (IQR: -54.8-3.5).
  
  
  
  These results support the use of the piezoelectric pedometers for walking and stair climbing types of activities, which are typical for OW/OB children in a nonlaboratory setting.
authors.affiliation: Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, Ontario, Canada.
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Hazell
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Montreal, Québec, Canada.
authors.forename: Caitlin V L
authors.initials: CV
authors.lastname: Ellery
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Montreal, Québec, Canada.
authors.forename: Tamara R
authors.initials: TR
authors.lastname: Cohen
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Montreal, Québec, Canada.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Vanstone
authors.affiliation: Children's Hospital, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Celia J
authors.initials: CJ
authors.lastname: Rodd
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Montreal, Québec, Canada.
authors.forename: Hope A
authors.initials: HA
authors.lastname: Weiler
mesh_terms: D056044:Actigraphy / Q000295:instrumentation* / Q000592:standards*; D000367:Age Factors; D000886:Anthropometry; D002648:Child; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000592:standards; D050177:Overweight / Q000628:therapy*; D063766:Pediatric Obesity / Q000517:prevention & control* / Q000628:therapy*; D015203:Reproducibility of Results; D016138:Walking