I can crack the very bottom of the thumb/side of my hand by holding it all the way around with my other hand and forcing the thumb upward. Usually the other thumb is placed right in or under the joint to get it to pop in.

yea… I have the same thing. Where I will want to be in one of those things that stretch the body. but like if it were around the breast area but under the arms and around the waste and it would just pull the back till it all cracked out. ahhh

I lay down flat or stand straight and press my heels together on the insides of the heel keeping my legs stiff forward and it usually pops my hips.