I have been meaning to ask this for a long time. About 6 months ago, I went bicycle riding after a long period of no riding. Nothing in particular happened as I recall. BUT...a few days later I noticed that when I first woke up in the mornings , my right thumb would jump in and out of the joint at the first bend (from the tip). It didnt hurt at all , just was amusing. Then my left thumb started doing it. Then few days later, the jump-out-jump-in motion started hurting. My thumbs would do it during the day any time I opened them out fully or picked up something in the wrong way. I bought some little metal finger braces at drug store and started wearing them while sleeping. Cant say that it helped, except it prevented me for waking up in pain while I reached for covers and my thumbs 'went out'. I tried to do some Internet research but everything seemed to be about thumb issues w/ the lower joint, the one where the thumb joins the hand. Here it is half a year later and my thumbs