Locomotion and Global Positioning System in Arterial Disease (Starter-GPS)

Study of Human Locomotion With Global Positioning System. Application to Patients With Peripheral Arterial Disease

The maximal walking distance (MWD) performed on treadmill (TT) remains the gold standard in estimating the walking capacity of patients suffering from peripheral arterial disease (PAD) 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 PAD patients.

The study has two main objectives, conducted together. Each objective include several phases. Objective 1: technical validation of GPS measurements in healthy subjects. phase 1: technical validation of a GPS device to study outdoor walking (completed). phase 2: comparison and use of various GPS devices (intra- and inter-GPS variability) in the study outdoor walking (on-going). phase 3: study of several factors that could influence accuracy of GPS measurements as walking speed, environment, sampling frequency and others technical features as the WAAS/EGNOS function (on-going). Objective 2: Application in PAD patients to study walking capacity under free-living conditions phase 1: comparison of GPS measurements (maximal walking distance) with the gold standard treadmill measurement of maximal walking distance (completed). phase 2: analysis of the variability of the walking capacity under free-living conditions from GPS measurements (completed). phase 3: study of reliability and sensibility (effect of treatment) of GPS measurements (on-going). phase 4: study of the relationship between laboratory measurements of walking capacity and GPS-derived parameters.

Analyse the clinical change after surgery from GPS measurements and compare it with laboratory measurement.

Validate the ability of GPS to detect walking and resting bouts and to accurately estimate walking speed and distance in normal subjects.

Measurement of maximal walking distance using GPS and comparison with treadmill measurement in PAD patients.

Inclusion Criteria: Ankle to Brachial Index (ABI) < 0.95 for PAD patients Age > 18 years old Able to walk on treadmill Exclusion Criteria: limb pain of potential non-vascular origin myocardial infraction in the last six months uncontrolled angina pectoris

Noury-Desvaux B, Abraham P, Mahe G, Sauvaget T, Leftheriotis G, Le Faucheur A. The accuracy of a simple, low-cost GPS data logger/receiver to study outdoor human walking in view of health and clinical studies. PLoS One. 2011;6(9):e23027. doi: 10.1371/journal.pone.0023027. Epub 2011 Sep 13.

Le Faucheur A, Noury-Desvaux B, Mahe G, Sauvaget T, Saumet JL, Leftheriotis G, Abraham P. Variability and short-term determinants of walking capacity in patients with intermittent claudication. J Vasc Surg. 2010 Apr;51(4):886-92. doi: 10.1016/j.jvs.2009.10.120.