It says in the game features, if you get shot in the leg you should be prone on the ground and forced to crawl. No matter how much Led damage you take, you will never be forced into prone. I tried jumping off of heights, shooting people in the leg and forcing them to move, but with the same result, They travel at the same speed.
- Legacy ID
Attempt to take any type of leg damage, you will never have to be prone.
Also, as a note, You will always end up dieing before you are even forced into prone. Even if you fall off a little cliff over and over. It will show your legs break, but you can still stand and run at full speed, but you will eventually just fall off and die.