title: Three-dimensional analysis of cervical spine motion: reliability of a computer assisted magnetic tracking device compared to inclinometer.
abstract: We aimed to investigate the reliability and reproducibility of a magnetic tracking technique for the assessment of overall cervical spine motion (principal and coupled movements). Ten asymptomatic male volunteers with a mean age of 29.3 years (range 20-37 years) were included in the study. Flexion, extension, left and right lateral bending and left and right axial rotation were measured using a magnetic tracking device (MTD) mounted onto a custom head-piece. For rotational movements in the frontal and sagittal planes the results were compared with the measurements of two standard inclinometers. Intra-observer, inter-observer and intra-instrument reliability was assessed with the intraclass correlation coefficient method. There were no significant differences for all motion measurements between the MTD and the inclinometer. High inter-observer reliability was found in flexion, extension, axial rotation and lateral bending indicating that the testing routine is applicable for different examiners. The intra-observer variability was high in flexion and extension, whereas in lateral bending the reliability coefficients were lower and displayed a fair to good reliability for most of the measurements with the MTD. The results of the MTD were found to be highly comparable with the inclinometer results with an inter-instrument correlation coefficient ranging from 0.88 to 0.99. The MTD is a reliable, reproducible method for three-dimensional motion analysis of the cervical spine and therefore a valuable method both for the clinical assessment of various degenerative and traumatic disorders and as a supplement of different therapeutic procedures and rehabilitation.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Ioannina, School of Medicine, University of Ioannina, 45100 Ioannina, Greece. idgelalis@msn.com
authors.forename: Ioannis D
authors.initials: ID
authors.lastname: Gelalis
authors.forename: Louis E
authors.initials: LE
authors.lastname: DeFrate
authors.forename: Kosmas S
authors.initials: KS
authors.lastname: Stafilas
authors.forename: Emilios E
authors.initials: EE
authors.lastname: Pakos
authors.forename: James D
authors.initials: JD
authors.lastname: Kang
authors.forename: Lars G
authors.initials: LG
authors.lastname: Gilbertson
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D006801:Humans; D008280:Magnetics; D008297:Male; D009068:Movement; D015588:Observer Variation; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D013122:Spinal Diseases / Q000175:diagnosis*; D013131:Spine / Q000502:physiology