One notable trait of Doohan's post-crash riding style was the use of a thumb-operated rear brake developed during 1993 owing to the reduced range of motion in his ankle. This was operated by a "nudge" bar similar to a personal water craft throttle, but mounted on the left handlebar. In 1999 Doohan had another accident, this time in a very wet qualifying session for the Spanish Grand Prix. He again broke his leg in several places and subsequently announced his retirement. Jeremy Burgess, Doohan's chief engineer for his entire career, later became Valentino Rossi's chief engineer. After Doohan retired he went to work as a roving adviser to Honda's Grand Prix race effort. At the conclusion of the 2004 season, Doohan and Honda parted company.