Tonight my hand cracked while I was turning on the kitchen sink. It was a very strang feeling. Anyways, I flexed my thumb, for whatever reason, and looked down at my thumb. Every few seconds or so, there would be a little twich go across the thenar muscle. It looked like a flicker. When I stopped flexing my thumb, and let my thumb rest, I couldn't see anymore twitches. By the way, I couldn't feel these twitches at all. Has anyone else had a similar experience where there thumb started twitching when flexed?