The thing to remember when diving is the following things.
is you have a bad knee then try sliding on your side instead of head on this way your legs won't bend in the same manner, hopefull eliminating any problems that you may have when sliding normally.
also a few more handy hints are as you go into the slide make sure you have one arm over your goggles so that if paint hits you there is a stronger possibility of it bouncing.
and finally this has probably already been said but make sure your hands hit the floor first taking all of your weight (your gun needs to be pointing up to prevent digging your barrel into the ground) followed by your chest, this way your legs shouldn't play any part in the slide
is you have a bad knee then try sliding on your side instead of head on this way your legs won't bend in the same manner, hopefull eliminating any problems that you may have when sliding normally.
also a few more handy hints are as you go into the slide make sure you have one arm over your goggles so that if paint hits you there is a stronger possibility of it bouncing.
and finally this has probably already been said but make sure your hands hit the floor first taking all of your weight (your gun needs to be pointing up to prevent digging your barrel into the ground) followed by your chest, this way your legs shouldn't play any part in the slide