Four Rules of Good Grip
In answer to the question of what constitutes the handle of handles, we would invite the questioner to, literally, try his hand and apply the “four rules of good grip.”
Thumb Guide
The thumb always seeks a direction. Traces of this search have already been found on the earliest prehistoric hand axes. Many objects for grasping are distinctly thumb-oriented.
Index Finger Rest
The forefinger is likewise in on the orienteering process. It acts as a pilot, paving the way for the rest of the hand to follow. We have located recesses for the forefinger on any number of artifacts.
Support for the Palm
The hand, as a unit, requires a support. The thumb and the index finger explore the environment. Then the entire hand is engaged in grasping. This is where the heel of the hand needs support, which is the only way to apply the hand�s force.
Volume
Hands do not like grasping into the void. They prefer to be guided around spherical shapes. They need volume. People unconsciously reveal this basic need when idly playing with treats for the hand, mostly colourful egg-shaped stones
