Objective: The full flexion to full extension angular ranges of motion (ROM) from C2 to C7 were measured for 78 normal subjects and 50 cervical myelopathic cases to examine the cervical motions for these two groups in a Chinese population.
Methods: Measurements were all taken from standard lateral radiographs.
Results: The normal group showed an average total ROM slightly less than in Western subjects, but a similar distribution of motion throughout C2 to C7. The proportion of motion at levels C4:C5 and C5:C6 were functions of the total ROM, the greatest proportion of motion being at C4:C5 for low (< 50 degrees) total ROM and moving to C5:C6 for high (> 90 degrees) total ROM. The myelopathic group showed a similar but less clearly established pattern of motion to this. A significantly lower average total ROM than in the normal group was also found.
Conclusions: This work suggests that the reduction in total angular ROM concomitant with aging results in the emphasis of cervical flexion-extension motion moving from C5:C6 to C4:C5, both in normal cases and those suffering from cervical myelopathy.