pedal

A pedal is a lever pressed by the foot or, less commonly, by the hand, to actuate a mechanism. The word derives from Latin pes, meaning foot. Pedals are a common interface in many devices, including transportation, musical instruments, and industrial machinery.

In bicycles, pedals are the rotating attachments to the crank and are connected to the rider by a spindle. They transfer leg power into the crankset and propulsion. Pedals come in several forms, including platform pedals with a flat surface, and clipless pedals that secure a shoe cleat. Toe-clip or strap pedals retain the foot on the pedal. Pedals use bearings or bushings and are made from metal or composite materials. Regular maintenance includes cleaning, lubrication, tightening, and inspection for wear, as worn pedals can slip or fail.

In music, a pedal is a foot-operated control that changes the instrument’s sound. On pianos, the sustain or damper pedal lifts the dampers to sustain notes; the soft pedal (una corda) narrows the tonal color; and the sostenuto pedal sustains selected notes. Modern pianos may offer half-pedaling for finer control. Pedals also appear on other keyboard and pipe organs, with varying effects.

Pedals are used in machinery and vehicles as control levers, such as throttles, clutches, or brakes, and in types of pedal-operated mechanisms. The term also appears in anatomy and botany for related foot-like structures, and in music theory as pedal points, which refer to a sustained note.