Integration of accelerometers, global positioning systems (GPS) and geographical information systems (GIS) for measuring physical activity

We tested the feasibility of integrating Actigraph accelerometers (AG), Global Positioning Systems (GPS) and Geographical Information Systems (GIS) to explore the physical activity in 26 healthy adults and 7 post-stroke individuals. The study subjects wore AG and GPS devices for 7 days. Feasibility outcomes were participants' experience of using these devices and data quality regarding i) valid and synchronized data between the AG and GPS; ii) GPS data distribution among participants living in areas characterized by differently developed built environments; and iii) time and intensity of physical activity in and outside the home. There were >10 hours of synchronized data between the devices and the majority (94%) of participants, irrespective of group, did not report any problems using the AG or GPS. Individuals living in low-density built environment had a higher percentage of GPS points closer to the home compared to those living in areas with high-density built environment where GPS scattering occurred. Although methodological challenges regarding scattering and GPS signal loss in densely built environment in urban areas, the results support the overall feasibility of integrating AG, GPS and GIS to investigate physical activity behaviour.