A stirrup is a light frame or ring that holds the foot of a rider, attached to the saddle by a strap, often called a stirrup leather. Stirrups are usually paired and are used to aid in mounting and as a support while using a riding animal (usually a horse or other equine, such as a mule). They greatly increase the rider's ability to stay in the saddle and control the mount, increasing the animal's usefulness to humans in areas such as communication, transportation and warfare.