How many fingers do you use to turn a knob?
How to use fingers during rotary control of columnar knobs
Designers watched people turn knobs of different sizes to learn how many fingers we use for each.
Ig Nobel 2022
Thirty-two students turned cylinders of many different diameters, from tiny knobs to big round handles, while the researchers noted which fingers they used and where they touched.
Small knobs got just a few fingertips, and bigger ones gradually recruited the whole hand, in a pattern neat enough to draw with a curve. Every volume dial and jar lid you meet owes something to this kind of work.
Somebody counted the fingers so your oven dial feels right.