What dangerous accident was common when a Penny-farthing struck an obstacle?

The rider would often be thrown head-first over the large wheel

The Penny-farthing, or ordinary bicycle, was inherently unstable because the rider sat perched very high, often five feet or more above the center of gravity, directly over the hub of the massive driving wheel. If the front wheel encountered even a minor obstruction like a stone or a rut, the momentum caused the entire machine to pitch violently forward. Since the rider was too high up to dismount quickly or regain balance, they were frequently launched head-first over the top of the giant wheel. This specific type of catastrophic fall was graphically known as 'taking a header' and was a primary deterrent for mass adoption.