You would be surprised how badly a riding crop to the thigh hurts, and little danger of permanent injury.
I had an uncle that followed racing horses around, working in the stables doing other such work. We were sitting on the couch once at my grandmother's place, watching TV. Out of nowhere gave me this sweeping big whack with one of those, right across the thighs. Hurt so bad I just sort of curled up and fell off the couch. Bastard thought it was hilarious.
