I have taken a .22 high velocity hp to the thigh at a range of about 18 inches. It was very hot, but not painful in the least. I was able to walk around after being shot, and would have still had 100 percent of my fight in me. It wasn't until around the 30 minute mark before it started hurting, and even then, my leg just stiffened up. The bullet struck bone, and slid down to just over my knee cap. I wasn't in any real pain until the day after, and even then it was minimal.
Not really a fan of the 22 or the 25 for defensive purposes. If you are stuck on using one, I would recommend the 22, and would also recommend head shots, or at least dump the mag into the chest. I'll stick with bigger bullets myself.
This my experience when I took a .22 mag to the leg from a NAA revolver. If the guy hadn't have done it by accident, I would have fed it to him before he could get it cocked again.
Luke