Historically, additional animals were sometimes used to brake very heavy vehicles on steep downhills, being hitched in harness breeching "behind" the load. This is still done when logging in very steep terrain. Breeching is not normally used for oxen in yokes, where braking is provided by pulling back on the yoke or girth (depending upon the type of yoke). On a light vehicle with shafts, "false breeching" is sometimes fitted to the vehicle, instead of using harness breeching. A horizontal strap is attached between the shafts of the vehicle, just behind the animal. When the animal slows or goes downhill, the vehicle runs forward, pushing the false breeching against the haunches of the animal, which can then push backwards to slow the vehicle. False breeching is generally limited to use with well-trained, steady animals, because if the animal rears or falls there is a risk of the false breeching running up over its back. It is sometimes used to help show off the animal's haunches, which would be partly covered by harness breeching. On both pack and riding stock, if breeching is used then generally a breastplate is used as well. Breeching may be used to stabilize the pack saddle of a packhorse or other pack animal, by keeping the saddle from sliding forward, especially on downhill tracks. Pack horse breeching may be supplemented with a crupper to provide additional stability. Breeching is occasionally used in a similar manner as that of a pack saddle, especially when riding mules. Mules often have lower withers and flatter backs than horses, making it likely that the saddle will slide forward when going downhill with a rider. However, a crupper is more commonly used on riding animals in general. An animal is often trained in harness with breeching before being hitched to a vehicle.