Thanks guy's I have been doing those exercises a bit probably I should do them more....
The thing is for those who didn't got the point, the standing up technic I have, it is shocking, once I stand up I can surf well I can actually ride the waves but the standing up technic is the reason why I cannot improve my surfing. I notice that when I surf decent size surf around 2 to 3ft max. i do it so quickly maybe because the face of the way, the speed, but I hardly notice my knee. In the other hand when i surf small waves is when i notice it a lot it does bother me, I try with a longboard and the same thing. Anyway thanks to those with constructive comment, appreciated

Anyway I wanted to comment about SUPS because last week I was surfing Grunters

and we were having such a good surf until a couple of SUPS come along and litterally stole every single wave. I got the ****s so much they should know that you cannot arrived to a spot and take over, show some respect for other surfers!!! They completly ruined the fun