Clinically acceptable agreement between the ViMove wireless motion sensor system and the Vicon motion capture system when measuring lumbar region inclination motion in the sagittal and coronal planes.
Wireless, wearable, inertial motion sensor technology introduces new possibilities for monitoring spinal motion and pain in people during their daily activities of work, rest and play. There are many types of these wireless devices currently available but the precision in measurement and the magnitude of measurement error from such devices is often unknown. This study investigated the concurrent validity of one inertial motion sensor system (ViMove) for its ability to measure lumbar inclination motion, compared with the Vicon motion capture system.



To mimic the variability of movement patterns in a clinical population, a sample of 34 people were included - 18 with low back pain and 16 without low back pain. ViMove sensors were attached to each participant's skin at spinal levels T12 and S2, and Vicon surface markers were attached to the ViMove sensors. Three repetitions of end-range flexion inclination, extension inclination and lateral flexion inclination to both sides while standing were measured by both systems concurrently with short rest periods in between. Measurement agreement through the whole movement range was analysed using a multilevel mixed-effects regression model to calculate the root mean squared errors and the limits of agreement were calculated using the Bland Altman method.



We calculated root mean squared errors (standard deviation) of 1.82° (±1.00°) in flexion inclination, 0.71° (±0.34°) in extension inclination, 0.77° (±0.24°) in right lateral flexion inclination and 0.98° (±0.69°) in left lateral flexion inclination. 95% limits of agreement ranged between -3.86° and 4.69° in flexion inclination, -2.15° and 1.91° in extension inclination, -2.37° and 2.05° in right lateral flexion inclination and -3.11° and 2.96° in left lateral flexion inclination.



We found a clinically acceptable level of agreement between these two methods for measuring standing lumbar inclination motion in these two cardinal movement planes. Further research should investigate the ViMove system's ability to measure lumbar motion in more complex 3D functional movements and to measure changes of movement patterns related to treatment effects.
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Hanne Leirbekk
HL
Mjøsund
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.|Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.
Eleanor
E
Boyle
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Per
P
Kjaer
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Rune Mygind
RM
Mieritz
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Tue
T
Skallgård
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. peter.kent@curtin.edu.au.|School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia. peter.kent@curtin.edu.au.
Peter
0000-0002-2429-9233
P
Kent
D000203:Activities of Daily Living; D000328:Adult; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008297:Male; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D012044:Regression Analysis; D015203:Reproducibility of Results; D012447:Sacrum / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000503:physiopathology*; D014741:Video Recording / Q000295:instrumentation*; D059015:Wireless Technology / Q000295:instrumentation*
Assessment; Bland Altman method; DorsaVi; Lumbar spine; Movement measurement; Validity