The newest improvement in cross-country safety is the "frangible" fence, which uses a pin and other techniques which allow the fence to "break or fall" in a controlled manner to minimize the risk of injury to horse and rider. This can help to prevent the most dangerous situation on cross-country, when the horse hits a solid fence between the forearm and chest, and somersaults over (rotational fall), sometimes falling on the rider. This type of fall has caused the deaths of several riders and horses.