flame_angel,
A little story for you.
I went surfing early January and while climbing over some rocks to get to some nice rolling swell I slipped and knocked my knee against a rock, continuing along my merry way I enjoyed a reasonable surf for 2 hours, apon trying to exit the water I found it hard to move the knee without grimacing. 2 days later I was in hospital with a rather large bacterial infection. 4 weeks later they cut the knee open and found a small piece of shell stuck in there.
The knee is still sore.
Go see a doctor now.
-E