Knee Locking Pulling My Knee Keeps Locking Up Randomly?

My Knee keeps locking up randomly? - knee locking pulling

I train in Parkour / Free Running and approximately 2 months, I did a dive roll in the grass, when I defend my knee click 3 times, and I think I had sprained knee, he was very excited, as it did when I switch, or ankle, but I was just supporting a close association in the last two weeks or less, because he keeps locking up. Is in bed, for example, changing the positions and BOOM! is not yet resolved. It's like something that moves on the left side of the left kneecap. After a while sitting and rubbing, with normal yields. its happens to be 2 to 3 times a week? But I do not know why?