When jumping over a hurdle in a race, many factors determine the faster runner. Obviously, taller people have an easier time with this but what is the reason for this? When a shorter person has to jump over a hurdle and literally jump to clear the hurdle a large time is spent in the air. This is wasted time that taller folks don't necessarily have worry about. When a person with longer legs clears a hurdle, they don;t actually jump. They merely open up their legs to clear the hurdle while their upper body remains in the same position with respect to the ground in the Y direction. This is a major advantage because when smaller people have to jump over the hurdle, they take a parabolic path that adds small amounts of time every hurdle they go over a hurdle.