I hadn’t thought about this until a recent conversation with Dr. Richard Gohl (Glendale, CA). He told me that when you get underneath the spinous process in the cervical spine to “lift” the subluxated vertebra onto the subadjacent segment, are you really adjusting that segment, or is your line-of-drive incorrect, and you are actually thrusting onto the subadjacent spinous? Are you doing what we do with imbricated thoracic spinouses wherein we get immediately inferior to the spinous above the subluxation and but contact and thrust on the subadjacent subluxated vertebra? That is what one does for the thoracic spine but not for the cervical spine.
As we know, if you do not get underneath a cervical spinous process and thrust, you can drive the subluxated vertebra more inferior, i.e., put the vertebra in more extension misalignment. Whenever you are adjusting via a spinous process contact in the cervical spine, make certain your contact is on inferior aspect of the spinous of the vertebra you intend to adjust AND that your thrust is I-S, P-A on that segment. That slight I-S component of the line-of-drive is so important to make certain you are not only reducing the posteroinferiority of the subluxated segment, but that the thrust is on the correct vertebra. It makes a lot of difference.