Behaving like a farmer often helps, ie shouting at them to shift and gesturing towards them to show them where you want them. Most important is to be confident, run away from them and they'll follow to see what you're up to (hence the feeling of being chased). In most cases they're more likely to tread on your foot or knock you over by accident whilst being nosy rather than deliberately trample you. Behave like you're the boss and they'll respond accordingly, providing you're not threatening a calf