How to manage a rearing horse

ground.
She was standing under a tree and hit a branch right on the poll between her ears and immediately stopped put her ears back and started shaking her head. I can only assume that the collision hurt andor scared her because she was never known for rearing again. She had regular vet and physio checks and didnt have any other lasting effects.
Thankfully none of my own horses have ever been known for rearing up. I have had a couple of exuberant Thoroughbreds who bunny hop which means the front legs come a couple of inches off the ground when being impatient or wanting to go faster such as when walking through a field. When I can feel them getting wound up beneath me I diffuse the situation by asking them to trot on. Insisting on walking could potentially lead to something like rearing. However I wont let a hopping horse gallop off because that rewards undesirable behaviour.