My in-laws' dog tripped me a few years ago - I had her and our dog in their backyard, trying to get them to play and work off some energy. I started to run, because that always gets my dog going, and their dog ran in front of me. She's a large dog, maybe 50 lbs.

I somehow kept myself upright, but I rammed my elbow into my own ribs in the process. It hurt for weeks!