4. Pressing elevator buttons with your knuckle
In order to avoid bacteria and viruses on public surfaces some people use the back of their hands, forearms, or even elbows to touch public surfaces. That’s an admirable effort, but not very effective, says Nidhi Ghildayal, PhD, an infectious disease researcher at the University of Minnesota.
“The thought process behind this habit is likely that less skin is being exposed to the unwanted germy surface,” she says, “but the back of your hand, just like your front, also has a likelihood of subsequently touching your face or other vulnerable areas. So using the back of your hand may or may not actually be helping you.”
