1610s, "lever (on an organ) worked by foot," from French pédale "feet, trick with the feet," from Italian pedale "treadle, pedal," from Late Latin pedale "(thing) of the foot," neuter of Latin pedalis "of the foot," from pes (genitive pedis) "foot," from PIE root *ped- "foot."
Extended to various mechanical contrivances by 1789. Pedal steel guitar is from 1969. Pedal-pushers "type of women's trousers suitable for bicycling" is from 1944.
When college girls took to riding bicycles in slacks, they first rolled up one trouser leg, then rolled up both. This whimsy has now produced a trim variety of long shorts, called "pedal pushers." ["Life," Aug. 28, 1944]