It’s widely believed that if you take a swing at a zombie with the business end of a shovel, it will not duck out of the way. Because of this, some mistakenly conclude that zombies don’t have any physical sensations whatsoever, going as far as to say that this lack of feeling is a physical advantage over normal humans.
In reality, a zombie with no physical sensation would be unable to move. Far from terrifying, this creature could do little more than lie on the ground and bite in your general direction. Physical sensation must be present for it to walk, grab, clutch, claw, tackle, chase, chew, bite, and effectively hunt the living.
However, they may not experience pain.
People with a rare nervous system disorder known as congenital insensitivity to pain with anhidrosis (CIPA) have no ability to sense pain, but they are able to feel pressure. Therefore, CIPA patients can navigate the world just as any other person does— they walk, run, play— but in doing so, they risk serious injury to themselves without even knowing.
CIPA sufferers often experience burns, broken limbs, and other self-inflicted wounds because their defensive reflex is largely shut off. Even though they can feel a knife going through their hand, it doesn’t hurt, so why avoid it?
In humans, CIPA can prove to be an extremely damaging condition. Teething infants chew their tongues and lips to bloody shreds. Toddlers play too rough and hurt themselves and others. Teens act even more recklessly than their peers, and the problems often get worse with age.
By contrast, in zombies this same trait would allow them to go to any length to accomplish their morbid objective of eating you and every other living human on the plane..