title: Utility of a step activity monitor for the measurement of daily ambulatory activity in children.
abstract: OBJECTIVE
  To evaluate the reliability and validity of the StepWatch Activity Monitor (SAM) as a reliable and valid measurement tool for assessing ambulatory activity in able-bodied children and to assess the ambulatory activity of able-bodied children.
  
  
  METHODS
  Descriptive study.
  
  
  METHODS
  General community.
  
  
  METHODS
  Ninety-seven able-bodied children, aged 6 to 20 years.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Anthropometric parameters, calibration of a step activity monitor to ensure accuracy, and 3 days of simultaneous heart rate and step activity monitoring.
  
  
  RESULTS
  The SAM had an accuracy of 99.87% compared with the observer-counted steps and was shown to be valid and reliable when compared with heart rate monitoring. The subjects in all age groups (6-10 y, 11-15 y, 16-20 y) spent most of their active time at low step rate but took the fewest steps at this rate. Although the least amount of time was spent at high step rate, it accounted for the most steps. The 6- to 10-year-old group took more total steps per day than any of the other groups. Boys spent significantly more time at high step rate than girls in all age groups (mean for boys, 66+/-4 min/d; girls, 47+/-4 min/d).
  
  
  CONCLUSIONS
  The SAM is an accurate, valid, and useful tool for measuring continuous, time-based step activity during real-world community activity for children and adolescents.
authors.affiliation: Rehabilitation Research and Training Center in Neuromuscular Diseases, Department of Physical Medicine and Rehabilitation, University of California, Davis, Sacremento 95817, USA. cmmcdonald@ucdavis.edu
authors.forename: Craig M
authors.initials: CM
authors.lastname: McDonald
authors.forename: Lana
authors.initials: L
authors.lastname: Widman
authors.forename: R Ted
authors.initials: RT
authors.lastname: Abresch
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Walsh
authors.forename: Denise D
authors.initials: DD
authors.lastname: Walsh
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D016138:Walking