Using the Microsoft Kinect™ to assess 3-D shoulder kinematics during computer use

Shoulder joint kinematics has been used as a representative indicator to investigate musculoskeletal symptoms among computer users for office ergonomics studies. The traditional measurement of shoulder kinematics normally requires a laboratory-based motion tracking system which limits, the field studies. In the current study, a portable, low cost, and marker-less Microsoft Kinectmi sensor was examined for its feasibility on shoulder kinematics measurement during computer tasks. Eleven healthy participants performed a standardized computer task, and their shoulder kinematics data were measured by a Kinect sensor and a motion tracking system concurrently. The results indicated that placing the Kinect sensor in front of the participants would yielded a more accurate shoulder kinematics measurements then placing the Kinect sensor 15 or 30 to one side. The results also showed that the Kinect sensor had a better estimate on shoulder flexion/extension, compared with shoulder adduction/abduction and shoulder axial rotation. The RMSE of front-placed Kinect sensor on shoulder flexion/extension was less than 10 for both the right and the left shoulder. The measurement error of the front placed Kinect sensor on the shoulder adduction/abduction was approximately 10 to 15, and the magnitude of error is proportional to the magnitude of that joint angle. After the calibration, the RMSE on shoulder adduction/abduction were less than 10 based on an independent dataset of 5 additional participants. For shoulder axial rotation, the RMSE of front-placed Kinect sensor ranged between approximately 15 to 30. The results of the study suggest that the Kinect sensor can provide some insight on shoulder kinematics for improving office ergonomics. (C) 2017 Elsevier Ltd. All rights reserved.