Never officially played team football in school, but had occasionally participated in "sandlot" (aka: city parks or schools) games. One weekend we got together at a nearby city park where there were always the local tough guys who got together and formed teams of roughly 6-7 guys on each side.
There was always the arguing and disagreeing about what a penalty actually was or how a certain type of play should be run. There was occasional blood from injury, and always much soreness and hurt afterward.
Regarding your original question about strangest sport-related injuries...
I was doing an end around to my right, was handed the ball, got loose to the outside and ran about 40+ yards before some younger, speedier neighborhood punk caught me from behind and dropped me before I got into the "endzone".
So... the injuries?
It
broke my heart because I didn't score, and
bruised my ego because some local yokel took me down! All in all, it was some pretty stupid but great fun, and most of the time we were pretty lucky nobody was ever seriously maimed!