DIAGNOSTIC-VALUE OF C2-3 INSTANTANEOUS AXES OF ROTATION IN PATIENTS WITH HEADACHE OF CERVICAL ORIGIN

Previous investigators have suggested that patients suffering headache stemming from the C2-3 segment of the cervical spine can be identifie d by detecting an abnormal axis of rotation of that segment. The prese nt study tested this hypothesis by correlating the location of the ins tantaneous axis of rotation (IAR) of the C2-3 segment with diagnostic blocks of the C2-3 zygapophysial joint in a sample of patients with he adache. We found no significant correlation between the location of th e axis and the response to diagnostic blocks. Previous false-positive assertions appear to be due to insufficient attention to the precision and reproducibility of the techniques used to determine IARs.