In sports, a false start is a disallowed start, usually due to a movement by a participant before being signaled or otherwise permitted by the rules to start. Depending on the sport and the event, a false start can result in a penalty against the athlete's or team's field position, a warning that a subsequent false start will result in disqualification, or immediate disqualification of the athlete from further competition.
A reduced starting lineup after Kamé Ali was disqualified due to a false start in heat 3 of the men's 110 metres hurdles at the 2012 London Olympics
Pressure-sensitive starting blocks at the start line of the 100 metres at the 2007 Pan American Games in João Havelange Olympic Stadium
Penalty (gridiron football)
In gridiron football, a penalty is a sanction assessed against a team for a violation of the rules, called a foul. Officials initially signal penalties by tossing a bright yellow colored penalty flag onto the field toward or at the spot of a foul.
NFL back judge Lee Dyer retrieves a penalty flag on the field during a game on November 16, 2008 between the San Francisco 49ers and St. Louis Rams.