What is the origin of the idiom "toe the line" and when to use it?

The origin of the idiom "toe the line" can be traced back to various sports, particularly track and field events. In these sports, competitors are required to position their toes on or behind a designated line before starting a race or performing certain actions, such as long jumps or shot puts. It is often used in professional settings such as workplaces, where employees are expected to follow established protocols, procedures, or company policies.