Article ID: 2026-0286
Introduction: Cervical spine movement can be evaluated using the range of motion (ROM) of lower (C2-7) and upper (C0-2, C1-2, and C0-1) cervical angles. Nevertheless, the relationships between cervical sagittal parameters and their ROMs and between lower cervical ROM and upper cervical parameters and ROMs remain unclear. This study investigated these relationships for a better evaluation of sagittal cervical spine motion.
Methods: Cervical sagittal parameters and their ROMs were measured on flexion, extension, and neutral lateral cervical radiographs of 42 healthy participants. Correlations between sagittal parameters and their ROMs and among different cervical ROMs were examined.
Results: In most participants, C0-1 ROM contributed positively in extension but negatively in flexion to C0-2 ROM. C0-2 and C1-2 angles correlated negatively with their respective ROMs. Participants with low C0-2 angle showed greater C0-2 extension and total ROM, greater C1-2 ROM, greater C2-7 angle, and lower flexion C0-2 ROM and total C0-1 ROM. C2-7 ROM strongly correlated with McGregor slope (MGS), C2 slope (C2S), and their respective ROMs.
Conclusions: In asymptomatic subjects, complex relationships exist among C0-1, C1-2, and C0-2 angles and their respective ROMs, with atypical movement patterns associated with compensatory mechanisms. Subjects with low C0-2 angle show greater extension and total C0-2 ROMs and lower flexion C0-2 ROM. C2-7 ROM correlated significantly with MGS ROM and C2S ROM. These findings must be confirmed in symptomatic patients. The effects of processes associated with decreased C2-7 ROM, such as cervical operations, disorders, and aging, on upper cervical and head movements must be investigated using extension, flexion, total C0-2 ROMs, MGS ROM, and C2S ROM.
