[theBadCormorant]

It would appear that "Kissing Spine" is a problem within horses, and has no relevance to the human spine.

From what I understand, the "Spinious Process" in a horse is much more pronounced than it is in humans; When the horse throws its head backwards (spinal extension), the Spinious Process can touch or "Kiss" each other, when this occurs it will lead to arthritic changes, pain and lameness.

Edit for clarity; The "Spinious Process" is the name given to the bony spur of the vertebrae that projects away from the centre of the body (backwards in humans, upwards in horses) - if you run your fingers down your spine, the bone you can feel is indeed very end of the Spinious Process.