Test-Retest and Intra-rater Reliability of Using Inertial Sensors and Its Integration with Microsoft Kinect™ to Measure Shoulder Range-of-Motion

This study determined the intra-rater and test-retest reliability of a novel motion-tracking system that integrates inertial sensors with Microsoft Kinect to measure peak shoulder range-of-motion (ROM) angles. Nine healthy individuals (6 female and 3 male, age: 36.6 +/- 13.3) with no shoulder pathology participated following ethical approval. Participants performed active shoulder forward flexion and abduction to the end of available range. Repeat testing of the protocol was completed after 7 days by the same rater. Results demonstrated excellent intra-rater reliability (ICC = 0.84, 0.93) for shoulder flexion and modest-excellent intra-rater reliability (ICC = 0.82, 0.52) for shoulder abduction. A high level of correlation was observed between week 1 and 2 for flexion and abduction (R = 0.85 0.93), expect for left abduction (R = 0.60). In conclusion, an inertial system combined with the Kinect is a reliable tool to measure shoulder ROM and has the potential for future research and clinical application.