title: Measurement of walking distance and speed in patients with peripheral arterial disease: a novel method using a global positioning system.
abstract: BACKGROUND
  The maximal walking distance (MWD) performed on a treadmill test remains the "gold standard" in estimating the walking capacity of patients who have peripheral arterial disease with intermittent claudication, although treadmills are not accessible to most physicians. We hypothesized that global positioning system (GPS) recordings could monitor community-based outdoor walking and provide valid information on walking capacity in patients with peripheral arterial disease.
  
  
  RESULTS
  We studied 24 patients (6 women) with arterial claudication (median [25th to 75th percentile] values: 57 years old [48 to 67 years], 169 cm tall [164 to 172 cm], weight 81 kg [71 to 86 kg], and ankle-brachial index 0.64 [0.56 to 0.74]). MWD on the treadmill was 184 m (144 to 246 m), which was compared with the results of self-reported MWD, the distance score from the Walking Impairment Questionnaire, MWD observed during a 6-minute walking test, and MWD measured over a GPS-recorded unconstrained outdoor walk in a public park. Self-reported MWD, Walking Impairment Questionnaire distance score, 6-minute walking test score, and GPS-measured MWD were 300 m (163 to 500 m), 28% (15% to 47%), 405 m (338 to 441 m), and 609 m (283 to 1287 m), respectively. The best correlation with MWD on the treadmill test was obtained with the MWD measured by the GPS (Spearman r=0.81, P<0.001).
  
  
  CONCLUSIONS
  Outdoor walking capacity measured by a low-cost GPS is a potentially innovative way to study the walking capacity of patients with peripheral arterial disease. It opens new perspectives in the study of walking capacity for vascular patients with claudication under free-living conditions or for physicians who do not have a treadmill.
authors.affiliation: Laboratory of Physiology, CNRS, UMR6214, INSERM U771, Medical School, University of Angers, Angers, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Le Faucheur
authors.forename: Pierre
authors.initials: P
authors.lastname: Abraham
authors.forename: Vincent
authors.initials: V
authors.lastname: Jaquinandi
authors.forename: Philippe
authors.initials: P
authors.lastname: Bouyé
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Saumet
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Noury-Desvaux
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D005080:Exercise Test / Q000295:instrumentation / Q000379:methods*; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000175:diagnosis / Q000503:physiopathology*; D012720:Severity of Illness Index; D013997:Time Factors; D016138:Walking