The blocks also enable the sprinters to adopt a more efficient starting posture and isometrically preload their muscles in an enhanced manner.
When George Simpson became the first person to run 9.4 seconds for the 100-yard dash in 1930, his record was disallowed because he used starting blocks.
Modern blocks used for world records now must have sensors that detect the pressure from the athlete and can be used to time their reaction to the starting gun.
Athletes who react faster than one-tenth of a second can be charged with a false start and the race recalled.
Some races for hearing-impaired athletes have also used starting light systems, similar to motorsport's Christmas Tree.