Validation of Attitude and Heading Reference System and Microsoft Kinect for Continuous Measurement of Cervical Range of Motion Compared to the Optical Motion Capture System.
OBJECTIVE
To compare optical motion capture system (MoCap), attitude and heading reference system (AHRS) sensor, and Microsoft Kinect for the continuous measurement of cervical range of motion (ROM).


METHODS
Fifteen healthy adult subjects were asked to sit in front of the Kinect camera with optical markers and AHRS sensors attached to the body in a room equipped with optical motion capture camera. Subjects were instructed to independently perform axial rotation followed by flexion/extension and lateral bending. Each movement was repeated 5 times while being measured simultaneously with 3 devices. Using the MoCap system as the gold standard, the validity of AHRS and Kinect for measurement of cervical ROM was assessed by calculating correlation coefficient and Bland-Altman plot with 95% limits of agreement (LoA).


RESULTS
MoCap and ARHS showed fair agreement (95% LoA<10°), while MoCap and Kinect showed less favorable agreement (95% LoA>10°) for measuring ROM in all directions. Intraclass correlation coefficient (ICC) values between MoCap and AHRS in -40° to 40° range were excellent for flexion/extension and lateral bending (ICC>0.9). ICC values were also fair for axial rotation (ICC>0.8). ICC values between MoCap and Kinect system in -40° to 40° range were fair for all motions.


CONCLUSIONS
Our study showed feasibility of using AHRS to measure cervical ROM during continuous motion with an acceptable range of error. AHRS and Kinect system can also be used for continuous monitoring of flexion/extension and lateral bending in ordinary range.
Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.; Interdisciplinary Program of Bioengineering, Graduate School, Seoul National University, Seoul, Korea.
Young Seop
0000-0003-3503-1627
YS
Song
School of Computer Science and Engineering, Seoul National University, Seoul, Korea.
Kyung Yong
0000-0003-2137-6018
KY
Yang
School of Computer Science and Engineering, Seoul National University, Seoul, Korea.
Kibum
0000-0002-4061-3157
K
Youn
Interdisciplinary Program of Bioengineering, Graduate School, Seoul National University, Seoul, Korea.
Chiyul
0000-0003-0754-058X
C
Yoon
Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Jiwoon
0000-0002-1431-9907
J
Yeom
Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.; Interdisciplinary Program of Bioengineering, Graduate School, Seoul National University, Seoul, Korea.
Hyeoncheol
0000-0003-4119-2742
H
Hwang
School of Computer Science and Engineering, Seoul National University, Seoul, Korea.
Jehee
0000-0003-1023-1868
J
Lee
Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.; Interdisciplinary Program of Bioengineering, Graduate School, Seoul National University, Seoul, Korea.
Keewon
0000-0001-6597-578X
K
Kim
AHRS; Joint range of motion; Kinect; Neck; Sensor