Several years back, when I was at music school, I had the bad habit of not taking the time to warm up. In turn, because of my, for lack of a better word, stupidity, I obtained a very painful ganglion cyst in my left wrist. It got to a point where it really began to hinder my playing. My finger stretch became very limited, and eventually my pinky finger was pretty much useless and nearly immobile. I continued without resting it.