The 2nd knuckle on my right hand locked up for the first time about 2 months ago. Since then, it always seems swollen and stiff, has locked up many more times, and I can t close my hand into a tight fist any more. Prior to this, I never had any aches/pains/stiffness in my knuckles. What might it be, what might have caused it, and what might help alleviate the pain and help regain my ability to grip and squeeze?