Catch and injuries

What is one of the more common injuries in Catch or submission wrestling?

Since rolling and starting on the knees i have had some weird knee clicking i dont know if the petela (knee cap) is just grinding or not. Anyone have any problems when wrestling with knees and how to prevent it? Knee guards?

Garry

Go get your knee checked to make sure nothing major is wrong.I've had surgeries on both knees and they still click,pop,and whistle.The doctor didn't see anything wrong with them on my last visit.Maybe check into some of the knee braces.Be careful ,chronic knee pain really sucks.Not trying to be negative or scare you,but seriously get it checked.
btw,one reason I don't like the guard ,is because I can't sweep .An elevator hurts me so bad I'll tap myself with it.

Thanks i will, it aint painful or anything but when on my knees it freaks me out when it moves aor clicks.

Garry