What is this brace used for?

I am about 2 1/2 months post op from a knee scope. I dislocated my kneecap and had a lateral release. I am now allowed to run on even ground and cheer, but just a little bit. My doctor isn't one to give knee braces, but I feel that my previous ones for other problems help me. Would this brace work for physical activity? If not, can you find me a good one?