title: Using the Microsoft Kinect™ to assess 3-D shoulder kinematics during computer use.
abstract: 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 Kinect™ 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.
authors.affiliation: Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, Raleigh, NC 27695, USA. Electronic address: xxu@ncsu.edu.
authors.forename: Xu
authors.initials: X
authors.lastname: Xu
authors.affiliation: Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, MA 01748, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Robertson
authors.affiliation: Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Karen B
authors.initials: KB
authors.lastname: Chen
authors.affiliation: Safety and Health Assessment and Research for Prevention (SHARP) Program, Washington State Department of Labor and Industries, WA 98504, USA.
authors.forename: Jia-Hua
authors.initials: JH
authors.lastname: Lin
authors.affiliation: Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, MA 01748, USA.
authors.forename: Raymond W
authors.initials: RW
authors.lastname: McGorry
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003201:Computers; D006804:Ergonomics / Q000295:instrumentation* / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012785:Shoulder Joint / Q000502:physiology*; D014584:User-Computer Interface; D014937:Work / Q000502:physiology*
keywords: Motion tracking; Office ergonomics; Shoulder biomechanics; Workstation design