flat feet horses - poor runners

Question
hello sir, hope you are having an idea of flat feet thoroughbred horses. i believe that they are poor runners in the race. am i correct? if yes, may i know why?

Answer
This is a conformation issue that affects some horses negatively and others not so much. A foot needs to have enough cup to absorb the energy by expanding until the sole flattens as it contacts the ground. A flat footed horse will be limited to this expansion and the foot will not allow enough energy absorption because the foot expansion is limited. Limited expansion also reduces the blood pumping properties of the frog. A softer racing surface, such as turf, will fell better physically to the horse as the surface will allow dissipation of energy rather than sending it back through the horse's leg.