Now I know you've all been a hairy situation on a horse where suddenly you're channeling your inner Lane Frost. Most riders try to balance themselves on a bucker or crow hopper by the reins, which isn't the most ideal. Cowboys of the old west had what is called a night latch for just those situations. A night latch is a safety strap that was made out of rope, leather, or even an old belt, which is attached to the saddle to help you stay on an out of control horse. You are using the strap to form a loop to grab like a suitcase handle or bareback rigging. The saddle horn is an option, but with a night latch, you can pull yourself down into the saddle, which gives you greater leverage than holding the horn.
The night latch got its name from night riders watching over cattle herds. The rider would sink one of his hands into the night latch, much like a bull rider does on a bull riding rig, primarily so that if he fell asleep he would not necessarily fall off.