Sore Knee Cant Straighten Knee Is Sore And "tight" After Bending Far One Way After Falling Down?

Knee is sore and "tight" after bending far one way after falling down? - sore knee cant straighten

Football practice yesterday, fell and bent my leg and where the heel touching the ass hard and fast, and it happened when I went, and now a little pain in the knee region. It felt as if his leg was locked in a bent position for long periods in a leg cast he feels funny, and down his legs when he finally leaves. it's like I'm stretching the knee, when I put my hand on my thigh and then lift the leg with his other hand. Do not bend (of course, her legs like that, but thats what im doing to try, as far as possible) nobody really knows what is happening "in technical or has an idea.