190524 playing piano
Image Credit: Supplied

Chris Harrison, Assistant Professor in Human-Computer Interaction Institute (HCII), Carnegie Mellon, and Gierad Laput, HCII PhD student, found that studying the various hand activities brought them to broadly segregating them into three types:

Atomic hand activities: These are hand movement that cannot be broken down into distinct stages. For example, wiping, scratching.

Examples of everyday atomic hand movements are:

  • Hands Still/Idle
  • Scrolling on Trackpad/phone
  • Typing on Keyboard
  • Swaying (while locomoting)
  • Typing on Phone
  • Moving/clicking mouse
  • Playing Piano
  • Using Scissors
  • Chopping Vegetables
  • Using Spoon (eating)

Compound: These are atomic hand activities that have multiple stages of movements to achieve a single purpose, such as eating and cooking. For example, the purpose of cooking in the which the hands engage is a combination of many atomic hand movements such as chopping or peeling vegetables.

Examples of everyday compound hand movements are:

  • Sign Language
  • Washing Dishes
  • Putting on clothes
  • Showering compound
  • Dancing compound
  • Cleaning compound
  • Putting Away Clothes
  • Doing Makeup compound
  • Kickboxing compound
  • Gesturing (while speaking)

Ambiguous: These hand activities could involve diverse appoaches. For example, when the hands open a bottle, they can either twist the cap off or use a bottle opener, which involve different movements though towards the same goal.

Examples of everyday ambiguous hand movements are:

  • Shaving
  • Counting notes
  • Adjusting watch
  • Putting on jacket
  • Putting on lotion
  • Stretching
  • Searching pocket
  • Opening door
  • Closing door
  • Reaching for an object

(Source: Sensing Fine-Grained Hand Activity with Smartwatches Gierad Laput and Chris Harrison, Carnegie Mellon University, Human-Computer Interaction Institute (HCII), 2019.)