title: In vivo three-dimensional kinematics of the cervical spine during maximal axial rotation.
abstract: The cervical spine exhibits considerable mobility, especially in axial rotation. Axial rotation exerts stress on anatomical structures, such as the vertebral artery which is commonly assessed during clinical examination. The literature is rather sparse concerning the in vivo three-dimensional segmental kinematics of the cervical spine. This study aimed at investigating the three-dimensional kinematics of the cervical spine during maximal passive head rotation with special emphasis on coupled motion. Twenty healthy volunteers participated in this study. Low-dose CT scans were conducted in neutral and in maximum axial rotation positions. Each separated vertebra was segmented semi automatically in these two positions. The finite helical-axis method was used to describe 3D motion between discrete positions. The mean (±SD) maximum magnitude of axial rotation between C0 and C1 was 2.5 ± 1.0° coupled with lateral flexion to the opposite side (5.0 ± 3.0°) and extension (12.0 ± 4.5°). At the C1-C2 level, the mean axial rotation was 37.5 ± 6.0° associated with lateral flexion to the opposite side (2.5 ± 6.0°) and extension (4.0 ± 6.0°). For the lower levels, axial rotation was found to be maximal at C4-C5 level (5.5 ± 1.0°) coupled with lateral flexion to the same side (-4.0 ± 2.5°). Extension was associated at levels C2-C3, C3-C4 and C4-C5, whereas flexion occurred between C5-C6 and C6-C7. Coupled lateral flexion occurred to the opposite side at the upper cervical spine and to the same side at the lower cervical spine.
authors: Université libre de Bruxelles (ULB), Department of Osteopathy, Faculty of Motor Sciences, 808 route de Lennik, 1070 Brussels, Belgium. wsalem@ulb.ac.be
authors: Walid
authors: W
authors: Salem
authors: Cyrille
authors: C
authors: Lenders
authors: Jacques
authors: J
authors: Mathieu
authors: Nicole
authors: N
authors: Hermanus
authors: Paul
authors: P
authors: Klein
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D019416:Head Movements / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D016683:Supine Position; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult