In thoroughbred horse racing, “clipped heels” occurs when a horse’s front legs make contact with the hind legs or heels of the horse running directly in front of it.
This dangerous situation typically happens when horses are running in tight quarters and one horse runs up too close behind another. The contact between the trailing horse’s front feet and the leading horse’s hind legs can cause the jockey to take up sharply on his horse, dramatically altering the horse’s stride. The horse may stumble or even fall instantly, the jockey may lose their stirrups in the process, and it can result in serious injuries to both horse and rider
The danger is increased by the toe grabs commonly used on racing plates in the United States, which help horses with traction. If the toe grab of one horse connects with another horse’s legs, they can become interlocked, causing an instant fall by taking the horse’s feet out from underneath them in milliseconds.