There is no movement animation in the game in the prone position, which depends on the state of health of the character.

Movement speed while walking and crouching changes based on HP. The character hobbles, his arms are weak, and his face has a painful grimace, but recently everything changes dramatically if the character lies down. The pain somewhere disappears along with weakness.

There used to be a similar mechanic in the game. It looked realistic and cinematic.

I hope this is a bug, and not a complete cut of mechanics from the game.