The leg straps or hopples worn by horses in the races, enable them to maintain an optimum stride and provide balance when under race pressure.
They do not, as is sometimes assumed, force the horse into an unnatural gait and most of the horses used for racing will pace instinctively without them.
The cart used for racing is a lightweight sulky and they come in a variety of high-tech designs. On a flat, firm surface the way in which they gain momentum is thought to eliminate any advantage that could otherwise be gained through the weight of the driver weight. Therefore in some races, horses are handicapped by trailing set distances (e.g. 10, 20 or 30 yards) at the start of the race and not by the weight they carry which is the norm in Thoroughbred racing.