What happens if your muscles stop working?
If a person's muscles stop working, that person would be totally immobilized. Yes, falling down would definitely happen; but when you hit the ground, you would not be able to do a darn thing about it.
This occurs in the body's muscles during strenuous exertion. It is the body's way to "get by" when it is pushed to its limit. Often cramping and stiffening of muscles are experienced after high lactic acid concentrations, in order to expel the acid from the muscles, and happens when the muscles stop working.