Flyball
Flyball is a dog sport in which teams of dogs race against each other from the start to the finish line, over a line of hurdles, to a box that releases a tennis ball to be caught when the dog presses the spring-loaded pad, then back to their handlers while carrying the ball. Flyball is run in teams of four dogs, as a relay. The course consists of four hurdles placed apart from each other, with the starting line from the first hurdle, and the flyball box after the last one, making for a length. The hurdle height is determined by the ulna's length or the smallest dog's shoulder height on the team (depending on the association). For example, under current North American Flyball Association (NAFA) rules, this should be below the withers height of the smallest dog, to a height of no less than and no greater than . United Kingdom Flyball League (UKFL) uses a patented ulna measuring device, measuring the distance between the 'elbow' and bone of the stopper pad with a minimum height of and a maximum of . Current EFC (European Flyball Championship) rules limit the height to no less than 17.5 cm and no