[souprock]

Your study does not address all types of injury.

I have seen more than a childbirth. I have 12 kids.

The most miserable and painful birth was in a hospital. That birth featured pain medication, fetal heart rate monitoring, beeping machines, and a prison-like situation with doors that locked us in. My wife was in pain for months afterward. We learned our lesson and didn't do another hospital birth.

The other 11 births were definitely not "so much pain", but pain did guide my wife to be careful. She was always up and about right afterward, without pain. One time she walked around town doing errands the next day.