#TIL there’s another way of touch someone with hand: with finger knuckle.
As a female student of a male coach, position of my body had to be fixed with physical touch when verbal instructions were not clear or understandable. Such a touch with knuckle sensed very differently from my back, it was not intrusive at all from my side. Also a knuckle is not able to get tactile perception as well as finger on the other hand. As a gesture, knuckle touch is much more polite. I never knew it till today.