The distinction between {tI’var} and {leQ} is not primarily foot vs. hand, though that’s often part of it. It’s the way the mechanisms work.

{leQ} refers to a device that you move in some direction (up or down, left or right: flip a switch, press a button) and, as a result of doing this, something happens (the light goes on, a doorbell rings). With some {leQmey}, some functions are accomplished by continuing to put pressure on the device (keep sliding the light switch until the lights dim to a desired level, keep pushing the power button until the computer comes back on), but then you let go and whatever outcome the switch was supposed to effect has come about; you don’t have to do anything more unless or until you want to change the outcome.

By extension, {leQ} is also a button on a touchscreen even though nothing physically moves.

In some (very) old cars, you’d turn the high-beam headlights on by pushing a button on the car’s floor with your foot. It was a button, not a pedal. And though you operated it with your foot, it would be a {leQ}.

With a {tI’var}, it’s generally the case that you have to keep pressure on the device so that it continues to do what you want it to do. Yes, you can release the gas pedal and the car keeps going, but it’s no longer accelerating, which is what pushing the gas pedal causes. (With cruise control, you’ve taken controlling-by-pedal out of the mix.)

{’olDop} and {jI’ev} are distinguished by how you use them (not what they’re used for). {’olDop} is the block you step on when you pedal a bike (not the whole mechanism); it’s definitely a foot thing. {jI’ev} is the thing you grab onto when turning a crank (also operating a door latch); it’s a hand thing.

Having said that, if an acrobat in a circus rides a bike standing on his head and operates the pedals with his hands, they’re still {’olDopmey}.