So, I can crack the 2nd and 3rd joints of my fingers just by flexing them. My thumbs don't crack, but I can push the first joint through the range of motion unt

So, I can crack the 2nd and 3rd joints of my fingers just by flexing them. My thumbs don't crack, but I can push the first joint through the range of motion until it locks and pushes the knuckle out the palm side. I can also push my shoulders out of their sockets, getting about another 2 inches of reach. Are my fingers and shoulders just strangely double jointed or is this something different?