I stayed on while mine did a sommersault down steep granite rubble, at 10,000+ feet in Ansel Adams, a long way from nowhere. Then my foot was caught while the terrified beast scrambled back up. In the slow motion tumble downward, my face heading for the edge of a log, I had plenty of time to think: 'If I get paralyzed, my wife is going to be so pissed." My eleven year old neighbor is having surgery today after having her foot caught in the stirrup while the horse ran - her head on the ground. Her jaw is broken. Turns out that horses are THE leading cause of little girl's broken bones.