title: Physical activity monitoring: addressing the difficulties of accurately detecting slow walking speeds.
abstract: OBJECTIVE
  To test the accuracy of a multi-sensor activity monitor (SWM) in detecting slow walking speeds in patients with chronic obstructive pulmonary disease (COPD).
  
  
  BACKGROUND
  Concerns have been expressed regarding the use of pedometers in patient populations. Although activity monitors are more sophisticated devices, their accuracy at detecting slow walking speeds common in patients with COPD has yet to be proven.
  
  
  METHODS
  A prospective observational study design was employed. An incremental shuttle walk test (ISWT) was completed by 57 patients with COPD wearing an SWM. The ISWT was repeated by 20 patients wearing the same SWM.
  
  
  RESULTS
  Differences were identified between metabolic equivalents (METS) and between step-count across five levels of the ISWT (p < 0.001). Good within monitor reproducibility between two ISWT was identified for total energy expenditure and step-count (p < 0.001).
  
  
  CONCLUSIONS
  The SWM is able to detect slow (standardized) speeds of walking and is an acceptable method for measuring physical activity in individuals disabled by COPD.
authors.affiliation: Institute for Lung Health, Department of Respiratory Medicine, Glenfield Hospital, University Hospitals of Leicester NHS Trust, Leicester LE3 9QP, UK. samantha.harrison@uhl-tr.nhs.uk
authors.forename: Samantha L
authors.initials: SL
authors.lastname: Harrison
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Horton
authors.forename: Robert
authors.initials: R
authors.lastname: Smith
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Sandland
authors.forename: Michael C
authors.initials: MC
authors.lastname: Steiner
authors.forename: Mike D L
authors.initials: MD
authors.lastname: Morgan
authors.forename: Sally J
authors.initials: SJ
authors.lastname: Singh
mesh_terms: D000368:Aged; D004734:Energy Metabolism; D005080:Exercise Test / Q000379:methods; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D055686:Metabolic Equivalent; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D015203:Reproducibility of Results; D016138:Walking
keywords: 6MWT; COPD; CV; Chronic obstructive pulmonary disease; ESWT; FEV(1); FEV(1)/FVC ratio; GOLD; ISWT; Incremental shuttle walk test; METS; PR; Physical activity; RER; Reliability and validity; SWM; Sensitivity; chronic obstructive pulmonary disease; coefficient of variance; endurance shuttle walking test; forced expiratory volume in 1 s/forced vital capacity; forced expiratory volume in 1 s; global initiative for obstructive lung disease; incremental shuttle walking test; metabolic equivalents; pulmonary rehabilitation; respiratory exchange ratio; six minute walk test; the multi-sensor activity monitor (SenseWear PRO2 Armband)