The knuckle on my right hand middle finger is swollen and looks bruised. I did not hit it. It is sore to the touch and I can not bend it all the way. Could this be arthritis? I bowl and use a finger tip ball. Could it be a muscle pull? TIA.
I wonder if you have broken a small blood vessel in or near the the joint because of the use with the ball.
I have had "spontaneous bleed" near a finger joint more than once and it has been quite painful and stiff (as you describe) for a few days. (The blood has not got much room to move so the finger swells and is painful).
I use some Lasonil cream (pharmacy product) if it happens. It's for relief of bruises, sprains and soft tissue injuries like what you describe. I really don't know if it heals much faster that way but I like to think so. It sound like you will have to practice with another finger for a little while. All best with it.