Over 50% of adults in the United States and over 40% of adults in Europe own a smartphone [1]. By 2016 it is expected that there will be one billion smartphone owners worldwide [2]. A smartphone is a mobile phone with a purposely built mobile operating system with advanced computing ability and interconnectivity compared with a standard mobile phone. Smartphones have more advanced Application Programming Interfaces (APIs) for running third party applications. They also contain technology that standard phones lack, such as portable media players, digital cameras, GPS navigation systems and modern web browsers. One key feature provided by smartphones relevant to this work is access to embedded sensors, such as gyroscopes, magnetometers and accelerometers.

When a series of wirelessly networked sensors are positioned on a human body, this is referred to as Wireless Body Area Networks (WBANs). Any sensor that can gather some form of physiological data can be integrated into a WBAN. Examples include piezoresistive sensors to measure breathing rate [3] and electrocardiograms used to measure heart rate. Physiological sensors integrated into a WBAN can be used for computer assisted rehabilitation [3], diagnosing illnesses and providing care for incurable conditions. WBANs promote non-invasive wireless monitoring, which allows patients to have increased levels of freedom. Subjects can be monitored constantly for symptoms at home, work or while on hospital grounds. WBANs also allow physiological changes in athletes to be monitored while they are in their preferred environment.

For instance, foot pressure insole technology allows track athletes to record foot pressure in their natural environment i.e., on the track, whereas previously pressure plate technology required the athlete to be in an unfamiliar scientific setting [4].Physiological data collected from WBANs can be used to ascertain the state and activity of a person independent of external infrastructure. This is called human activity recognition and it is important in various applications such as monitoring the health and security of the elderly who live alone for example, with a goal of improving their quality of life, freedom and safety [5]. One application that is beginning to receive attention is the benefit that activity recognition technology can give to athletes [6].

Here activity recognition can help athletes gather performance metrics quickly and easily, help physiotherapists identify possible injury concerns Dacomitinib and give coaches detailed information on their players’ fitness and ability.Much of the research completed in WBAN activity recognition has dealt with detecting everyday tasks such as eating, ascending and descending staircases, sitting, brushing teeth as well as motion activities such as walking, jogging and running [7�C9].