Dexterity

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Overview | Understanding dex. | Dex. functions (5) | Env. context | Design guidance | Pop. stats. (2)

Dexterity functions

Introduction | Pushing | Pinch gripping | Power gripping | Two-handed tasks

The most critical dexterity functions for product interaction are now considered. A single hand can be used to generate a

  • Push force using any part of the hand
  • Pinch grip using the index finger and thumb to generate opposing forces
  • Power grip using the palm and thumb together with all four fingers

A push force requires the least amount of dexterity capability because there is no need for an opposing grip. Two-handed tasks require the use of both hands to perform a combination of pushing or gripping. One hand is often required to hold or stabilise the object, while the other performs fine precision movements.

A person pushes a button easily with one finger, compared to a person picking up a Scrabble piece which requires a grip between thumb and forefinger.

A push with no grip requires the lowest dexterity capability whereas holding and lifting a Scrabble piece requires a pinch grip with relatively low force

A person squeezes a tube of cream, compared to a person twisting open a fizzy drinks bottle.

Squeezing cylindrical products requires a power grip, whereas opening a bottle requires a high force pinch grip from one hand, and a power grip from the other