I think about it like this. A serious martial artist probably feels safe in almost any situation, knowing that he could defend himself under most circumstances with just his brains and bare hands. In the rock/scissors/paper hierarchy of the dangerous world out there, 22 LR beats Bare Hands. So I'd feel comfortable with 22LR. Yes, I'd rather have a 9 or .357, but if a 22 was what I was carrying, it would provide a lot of comfort in a bad situation.
I have known people who had been shot with 22LR, and they were messed up BAD. Yes, I know, it doesn't have the stopping power of larger calibers. And there are always stories floating around about people who were shot with a 22, or 9, or 38, or whatever the caliber-to-be-bashed-of-the-conversation happens to be, who immediately after receiving multiple wounds by these rounds, shrug off the pain and climb Everest or something.
But I still contend that anyone getting shot with a 22 is almost always messed up BAD, and any bullet is still much more effective and deadly than any fist or foot or other non-firearm weapon.
FWIW
David