Hiya - some technical anatomical jargon for you first - a sublux (as we tend to call them, though it should really be called a subluxation
) is a partial dislocation, where the joint or an area where two or more bones meet (i.e ribs) move out of position, but not completely out of the joint capsule or past the next bone. A full dislocation is when the bones move completely out of position.
Snapping, crunching, popping and various other exiting noises we get are due to our joints moving about so much, but what it is exactly that is causing each specific noise is up for argument - air in the joints (controversial
), bones crunching, ligaments/tendons snapping.
We do have a long thread on dislocating/subluxing - what is the difference - where people discuss how they experience their various lovely injuries
Subluxing/ating (depending on how you want to spell it) can occur without noticing, it can even occur without pain. I can sublux the same kneecap both with and without pain within half an hour, it depends very much on whether I am weight-bearing on the leg at the time, as to whether it hurts (or how much it hurts). My shoulder slides in and out constantly and I only notice it's out when I twist my arm to check every 10 minutes or so (the pain is pretty permanent in that shoulder now) and it pops back in. Some things are a bit more dramatic though,such as my recent realisation that I can sublux my tibia from my femur (bottom of leg from top of leg, at the knee) that was ridiculously painful and helpfully dislocated my kneecap at the same time.
Sorry if I havn't been too helpful. I think the best description I can come up with is the joint just feels wrong, even if it's not painful. It feels creepy and wrong, definitely feels out of position (when you can actually still feel positional data in that joint) and can often be painful, but the acute pain is often short-lived if there is little tissue damage from the sublux.