When I was younger I drove an ambulance, and even though we wore latex gloves at all times, during our training a senior EMT went over handwashing protocol: Thoroughly soap and rinse every square inch of your fingers, palms, back-of-hands and wrists. We were also instructed to hum the entire song “Yankee Doodle Dandy” in our heads as we did it; if we finished washing before we got to the end of the song, we didn’t do a thorough job.
Now that the Coronavirus/COVID-19 is spreading around the globe, Kottke dug up a medical reference diagram that shows the parts of the hand most people miss during casual washing:
Listen beautiful relax classics on our Youtube channel.
Using data from a 1978 study on the hygiene of health professionals, this is a map of the most missed areas when washing hands.
This more recent paper contains a short review of various studies of missed areas, most of which conclude that people often forget to wash their fingertips.
By the bye, during that training session mentioned above, I told the old-timer EMT that I didn’t know the song “Yankee Doodle Dandy;” he said humming the Alphabet song at a measured pace worked out to the same length. For their part, the CDC says the “Happy Birthday” song, two times in a row, will also do the trick.