I gave a girl a porcelain ring when I was about 9. She had a playground incident and he finger swelled up so bad that EMS could not get the ring off. The ER had to freeze her finger and then they used a vise to break the ring.
Just this summer, I went to Denver to drop off the family at the airport. I spent the night with a friend and we decided to rent a small trib and run Boulder Creek through town. On our second run, I had parked the car on a parallel incline. We got the raft off and were about to shuttle the car down to the kayak park. As my buddy got in the car, his left hand was on the top of the car to get in. I had gotten in and was closing the drivers side door. The concussion from me closing the door, made the passenger side door close on his hand. We immediately talked about pain and swelling and I mentioned he should take off his ring. He felt good on the water, but as soon as we were done for the day, his finger swelled up. His thoughts a month later were that the ring helped in stopping the full force of the door, he believed that his finger was probably still broken, but not to the extent that he needed medical attention that day.
I hardly wear my ring due to it being a little big and the nature of the sports I play and job I do. I have considered the tattoo as an alternative, but have not gone there yet.