Hi, I'm Aura.
Conceptual hit boxes, not for anything but just an idea for penalties for being shot in particular places on the body, inspired by SWAT4. This is also assuming the shooter is right handed.
Upper leg injury penalties will not stack
Penalties not shown
Anywhere shot in the arm/hand: Slower weapon switching.
Anywhere shot in the legs: Slower stance switching.
Everything of course will include health loss.
Image credit: Imageshack.us