=====Cervical motion=====
Cervical motion segment contributions to head motion change over the full [[ROM]] and cannot be accurately characterized solely from endpoint data. The continuously changing segmental contributions suggest that the compressive and shear loads applied to each motion segment also change over the ROM. The clinical implication of increased contributions from the inferior motions segments near the end ROM is that the clinician may advise the patient to avoid end ROM positions to lessen the demand on the discs of inferior motion segments
((Anderst WJ, Donaldson WF 3rd, Lee JY, Kang JD. Cervical motion segment
contributions to head motion during flexion\extension, lateral bending, and axial
rotation. Spine J. 2015 Dec 1;15(12):2538-43. doi: 10.1016/j.spinee.2015.08.042. 
Epub 2015 Aug 31. PubMed PMID: 26334229.)).

see [[Cervical axial rotation]].

The use of motion-preserving [[spinal implant]]s versus conventional [[arthrodesis]] instrumentation systems, which stabilize operative segments, necessitates improved understanding of their effect on spinal [[kinematics]] and the biomechanically optimal method for surgical reconstruction.