Joint position sense - There's an app for that

Traditionally, proprioception has been assessed with a passive model, in which an external apparatus moves a body segment. Recently, protocols have been developed based on active movements, which are more representative of functional activities. However, even these approaches require expensive testing equipment and the necessity of a visit to a research lab, as there are no commercially available mobile instruments that allow for the assessment of proprioception outside of a laboratory setting. The objective of this study was to demonstrate the validity and feasibility of using a mobile device (iPod Touch) to assess joint position. We conducted a concurrent validity study in the lab (n=9) and a field based study (n=79). The field based study was conducted at the 2012 American Society of Biomechanics meeting in Gainesville, Florida. The results of both studies demonstrate good agreement with our established protocol using a magnetic tracking device, with angular errors decreasing with increasing shoulder flexion angles. The studies demonstrate the validity and feasibility of using mobile devices for assessing motion-based parameters, both inside and outside of a laboratory setting.