I jammed my finger over 1 and 1/2 months ago, don't have pain, but movement is jerky, what is my problem?

It hurt for maybe week, and after that, I might have the occasional shooting pain, but it felt pretty normal as far as pain goes after about three weeks. I don't have pain anymore, but when I bend my finger, I can't bend it in a smooth motion like normal, at least not normally, most of the time it bends in a jerky motion. Do you know why this might be?