Reliability and criterion validity of the "Gyroscope" application of the iPod™ for measuring lumbar range of motion.

Background: Recent technologies, such as the iPod, are often equipped with an accelerometer and magnetometer, which, through software applications, can perform various inclinometric functions. These applications have the potential to measure and quantify range of motion (ROM).

Objective: The purpose of this study was to estimate the iPod "Gyroscope" application intra- and inter-rater reliability as well as its criterion validity in healthy participants lumbar ROM assessment.