Objective measurement of simulated lifestyle activities in adults with lower limb absence : Reliability and validity of the activPAL™ accelerometer during simulated lifestyle activities

Being physically active is one of the most important components of successful health promotion. Physical activity has long been a priority for public health, rising to greater prominence with the publication of the global recommendations on physical activity for health (World Health Organization, 2011). Mobility limitation can be typically defined as reported difficulty walking for one-quarter mile or climbing one flight of stairs (Verbrugge & Jette, 1994). Increasing physical activity and reducing sedentary behaviour among those with mobility limitations has also been shown to improve health outcomes and control the economic and social burden of lifestyle-related disease (Loprinzi, Sheffield, Tyo, & Fittipaldi-Wert, 2014). Measuring physical behaviour in people with limb absence is necessary to identify those at risk of health deterioration. Further, understanding where and how best to direct physical behaviour interventions aimed at increasing physical activity and reducing sedentary behaviours is important. The term physical behaviour in the context of this research encompasses both sedentary behaviour and physical activity. The Sedentary Behaviour Research Network defined sedentary behaviour as “any waking behavior characterized by energy expenditure ≤ 1.5 METs while in a sitting or reclining posture” (Sedentary Behaviour Research Network, 2012). Similarly, this research study does not encompass sleeping behaviour. This research focuses on sedentary and physical activity concepts of the movement continuum and patterns of sedentary and physical activity behaviour during waking hours.