Acupunct Search


J Acupunct Res > Volume 31(1); 2014 > Article
Ahn, Kim, Youn, Lee, Shin, Kim, Park, and Park: Test-retest Reliability and Intratest Repeatability of Measuring Lumbar Range of Motion Using Inertial Measurement Unit※
See the Original "".


Objectives :

The purpose of this study is to estimate the test-retest reliability and the intratest repeatability in measuring the lumbar range of motion of healthy volunteers with wireless microelectromechanical system inertial measurement unit(MEMS-IMU) system and to discuss the feasibility of this system in the clinical setting to evaluate the lumbar spine movement.

Methods :

19 healthy male volunteers were participated, who got under 21 points at oswestry disability index(ODI) were adopted. Their lumbar motion were measured with IMU twice in consecutive an hour for the test-retest reliability study. Intratest repeatability was calculated in the two tests separately. The calculated intraclass correlation coefficients(ICC) were discussed and compared with the those of the previous studies.

Results :

Lumbar range of motion of flexion 41.45°, extension 16.34°, right lateral bending 16.41° left lateral bending 13.63° right rotation −2.47°, left rotation −0.61°. ICCs were 0.96∼1.00(intratest repeatability) and 0.61∼0.92(test-retest reliability).

Conclusion :

This study shows that MEMS-IMU system demonstrates a high test-retest reliability and intratest repeatability by calculated intraclass correlation coefficients. The results of this study represents that wireless inertial sensor measurement system has portable and economical efficiency. By MEMS-IMU system, we can measures lumbar range of motion and analyze lumbar motion effectively.


This study was supported by a grant of the Korean Health Technology R & D Project(HI13C0510) Ministry of Health & Welfare, Republic of Korea

Fig. 1.
Depicts the flow chart for the method of a study based on a report of the average lumbar range of motion of 19 healthy volunteers with microelectromechanical system inertial measurement unit
Fig. 2.
Microelectromechanical system inertial measurement unit transmitter
Fig. 3.
Photograph of 2 microelectromechanical system inertial measurement unit transmitters attachment locations
L1 spinous process and between posterior superior iliac spine.
Fig. 4.
A screenshot of basic posture, flexion, extension, right lateral bending, left lateral bending and right rotation movement from the sample movie
Fig. 5.
A sample graph of a lumbar flexion movement
Green line symbolizes lumbar flexion movement. Each volunteer performed the flexion movement 3 times.
Fig. 6.
A sample graph of a lumbar extension movement
Blue line symbolizes a lumbar extension movement.
Each volunteer performed the extension movement 3 times.
Fig. 7.
A sample graph of a right lateral bending movement of lumbar
Red line symbolizes right lateral bending movement.
Each volunteer performed the right lateral bending movement 3 times.
Fig. 8.
A sample graph of right rotation movement of lumbar. Orange line symbolizes right rotation movement. Each volunteer performed the right rotation movement 3 times
Table 1.
Evaluation Circumstances
Space Indoor space(5×5 m)
Environment 2 microelectromechanical system inertial measurement unit transmitters
1 radio frequency receiver
1 computer with LabVIEW to receive data
1 computer for watching a sample movie
1 pair of slippers
1 pair of trousers
2 staff members 1 staff for information process
1 staff for attachment transmitters to subjects and alignment motion of subjects
Aid for assessment tool Oswestry disability index questionnaire
A sample movie (basic posture, flexion, extension, lateral bending and rotation)
A script of verbal order
Table 2.
Lumbar Range of Motion and Reliability
Motion First Experiment Second Experiment Comparison between the first experiment and second experiment
M (SD) ICC (2,1)a 95 % CI M (SD) ICC (2,1)a 95 % CI M (SD) ICC (2,2)b 95 % CI
Flexion 41.75 (7.70) 1.00 0.99∼1.00 41.15 (8.33) 1.00 1.00–1.00 41.45 (7.92) 0.71 0.24∼0.89
Extension −15.40 (6.26) 0.99 0.97∼1.00 −17.28 (7.66) 0.99 0.98–1.00 −16.34 (7.03) 0.61 0.00∼0.85
Right Bending 16.39 (3.14) 0.96 0.89∼0.98 16.42 (3.72) 0.95 0.86–0.98 16.41 (3.36) 0.84 0.58∼0.94
Left Bending −13.67 (3.99) 0.99 0.99∼1.00 −13.60 (3.65) 0.99 0.96–0.99 −13.63 (3.81) 0.90 0.73∼0.96
Right Rotation −2.93 (3.06) 0.98 0.95∼0.99 −2.00 (3.98) 0.97 0.92–0.99 −2.47 (3.53) 0.92 0.77∼0.97
Left Rotation 0.04 (3.92) 0.95 0.88∼0.98 −1.27 (4.51) 0.97 0.91–0.99 −0.61 (4.19) 0.87 0.65∼0.95

M : mean(°). SD: standard deviation(°).

ICC : intraclass correlation coefficient. CI: confidence interval.

a intratest repeatability, ICC(2,1), agreement.

b test-retest reliability between 1 hour, ICC(2,2), agreement.

The second experiment was carried out after 1 hour.

VI. References

1. Neuman DA. Kinesiology of the musculoskeletal system. Seoul: Jungdam media. 2010:3–26.

2. Kim H, Shin SH, Kim JK, Park YJ, Oh HS, Park YB. Cervical coupling motion characteristics in healthy people using a wireless inertial measurement unit. Evidence-based Complementary and Alternative Medicine. 2013;art. no. 570428.
crossref pmid pmc pdf
3. Klein AB, Snyder-Mackler L, Roy SH, DeLuca CJ. Comparison of spinal mobility and isometric trunk extensor forces with electromyographic spectral analysis in identifying low back pain. Phys Ther. 1991;71:445–54.
crossref pmid
4. Mayer TG, Tencer AF, Kristoferson S, Mooney V. Use of noninvasive techniques for quantification of spinal range-of-motion in normal subjects and chronic low back dysfunction patients. Spine. 1984;9(6):588–95.
crossref pmid
5. Hunt DG, Zuberbier OA, Kozlowski AJ, et al. Reliability of the lumbar flexion, lumbar extension, and passive straight leg raise test in normal populations embedded within a complete physical examination. Spine. 2001;26(24):2714–8.
crossref pmid
6. White AA 3rd, Panjabi MM. The basic kinematics of the human spine: A review of past and current knowledge. Spine. 1978;3(1):12–20.
crossref pmid
7. Panjabi MM, Oxland TR, Yamamoto I, et al. Mechanical behavior of the human lumbar and lumbosacral spine as shown by three-dimensional load-displacement curves. J Bone Joint Surg Am. 1994;76A:413–24.
crossref pmid
8. Barthes X, Walter B, Zeller R, et al. Biomechanical behaviour in vitro of the spine and lumbosacral junction. Surg Radiol Anat. 1999;21(6):377–81.
crossref pmid
9. Tojima M, Ogata N, Yozu A, Sumitani M, Haga N. Novel 3-dimensional motion analysis method for measuring the lumbar spine range of motion. Spine. 2013;38(21):E1327–33.
crossref pmid
10. Hindle RJ, Pearcy MJ, Cross AT, et al. Three-dimensional kinematics of the human back. Clin Biomech. 1990;5(4):218–28.
11. Al-Eisa E, Egan D, Deluzio K, Wassersug R. Effects of pelvic skeletal asymmetry on trunk movement: Three-dimensional analysis in healthy individuals versus patients with mechanical low back pain. Spine. 2006;31(3):E71–9.
crossref pmid
12. Jeong WH, Jee HM, Park JH. Real-time 3-Dimensional Measurement of Lumbar Spine Range of Motion using a Wireless Sensor. Journal of Institute of Control, Robotics and Systems. Journal of Control, Automation, and Systems Engineering. 2012;18(8):713–8.
13. Ha TH, Saber-Sheikh K, Moore AP, Jones MP. Measurement of lumbar spinal posture and motion using inertial sensors-A protocol validity study. Manual Therapy. 2013;18(1):87–91.
crossref pmid
14. Kim HH, Kim KW, Park JM, et al. Test-retest Reliability and Intratest Repeatability of Measuring Cervical Range of Motion Using Inertial Measurement Unit. The Acupuncture. 2013;30(4):25–33.
crossref pdf
15. Fairbank JC, Couper J, Davies JB, et al. The Oswestry low back pain disability questionnaire. Physiotherapy. 1980;66(8):271–3.
16. Kim DY, Lee SH, Lee HY, et al. Validation of the Korean Version of the Oswestry Disability Index. Spine. 2005;30(5):E123–7.
crossref pmid
17. Pinsault N, Vuillerme N. Test-retest reliability of centre of foot pressure measures to assess postural control during unperturbed stance. Med Eng Phys. 2009;31(2):276–86.
crossref pmid
18. Schuit D, Petersen C, Johnson R, Levine P, Knecht H, Goldberg D. Validity and reliability of measures obtained from the OSI CA-6000 Spine Motion Analyzer for lumbar spinal motion. Manual Therapy. 1997;2(4):206–15.
crossref pmid
19. Dvořak J, Vajda EG, Grob D, Panjabi MM. Normal motion of the lumbar spine as related to age and gender. European Spine Journal. 1995;4(1):18–23.
crossref pmid
20. Kendall FP, Kendall EM, Provance PG. Muscles: testing and function with posture and pain. Seoul: Pureunsol. 2001:81–9.

21. Marras WS, Lavender SA, Leurgans SE, et al. The role of dynamic three dimensional trunk motion in occupationally related low back disorders: the effects of workplace factors, trunk position, and trunk motion characteristics on risk injury. Spine. 1993;18(5):617–28.
crossref pmid

Article and Issues
For this Journal
For Authors
Submit Manuscript
Editorial Office
Gil Korean Medical Hospital, Gachon University
Keunumul-Ro, Chung-Ku, Inchoen 22138, Korea
Tel: +82-70-7606-6353,4    Fax: +82-32-232-3334    E-mail:                

Copyright © 2021 by Korean Acupuncture & Moxibustion Medicine Society. All rights reserved.

Developed in M2community

Close layer
prev next