Measuring Contextual Factors that Influence Real-World Walking Speed

Walking Speed (WS) has been called the 6th vital sign, with the potential to predict functional decline and mortality in the elderly and infirm. Current approaches to monitoring involve measuring the distance covered over a given time, usually in a hospital setting, however these assessments are brief and performed infrequently, The advert of ubiquitous wearable devices offers the possibility to monitor WS constantly and on a population scale. However, such real-world WS (RWS) is influenced by multifarious Contextual Factors (CF), these need to be considered in order to determine the potential health cause of RWS deterioration. This paper presents the key Environmental CF (ECF) that influence RWS, and the methodology to estimate these ECF by combining mobile phone GPS data with various publicly available OpenData GIS resources.