DK

It is possible that your knee clicking and stiffness could be related to a muscle spasm/knot in your lower back. Many of the muscles that move our legs originate in the pelvic girdle (attach to the pelvis), and when a muscle gets irritated it sometimes spasms at the origin (especially after a fall or odd movement). when this happens the muscle shortens a bit, and you can imagine how it could pull the entire knee out of alignment. I've written about this elsewhere, but I've had the knee "clicking" problem that you mention and was able to make it go away by massaging the muscles in my sacroiliac region.

MNS