Karen O’connor of the U.S. riding Mr Medicott performs during the equestrian Eventing Individual Dressage Day 1 in the Greenwich Park during the London 2012 Olympic Games

Karen O'Connor of The Plains, Va., competes. (Mike Hutchings/Reuters)

Karen O’Connor of The Plains, Va., competes. (Mike Hutchings/Reuters)

Karen O’connor of the U.S. riding Mr Medicott performs during the equestrian Eventing Individual Dressage Day 1 in the Greenwich Park during the London 2012 Olympic Games, July 28, 2012. REUTERS/Mike Hutchings (BRITAIN – Tags: SPORT EQUESTRIANISM OLYMPICS)