The performance of Kinect in assessing the shoulder joint mobility

Motor impairments affecting old people require a regular and reliable monitoring of the body functional autonomy. Low cost camera-based systems, initially designed for entertainment applications, have been evaluated for a possible adoption in diagnosis and rehabilitation. Unfortunately, their adoption is partially hampered by noise, precision and accuracy issues. In this paper we evaluate the performance of the Kinect One sensor in assessing the shoulder joint mobility in subjects with different body sizes: we measure the maximum angle reached by a patient raising his/her arms, the time needed to perform such action and the time the patient is able to keep his/her arms up. The preliminary tests conducted on two healthy subjects revealed no significant difference in terms of relative error among measures collected for subjects with different body heights and sizes. However, statistical tests suggested a correlation between the relative errors on large angle amplitudes and the time spent with arms up.