Motto
The human hand is an inseparable part of the self and thereby a manifestation of the self in the world. Postures and motion have their natural boundaries that seem to be fine tuned to the evolutionary, socially and individually developed abilities of man to grasp, to use tools, to gesture and to caress.
Goal
The goal of this project was to develop a human hand model that simulates natural anatomy in its looks and its motion.
Natural Motion Space of Human Hand Motion in a closed Taxonomy
Based on our research we propose a Taxonomy that has two essential natural motion dimensions: Extension-Flexion and Abduction-Adduction. They have Apposition-Opposition in common.
The boundaries of the Taxonomy are formed by two essential hand motions:
- Main Clenching motion
Fully extended and abducted the fingers start (1, a) and flex, via the Large Grasp (b) into a Fist (3, c).
- Complementary Containing motion
All adducted fingers move from extension (3, a) to flexion and end via a Cup (3, b) into a Cage (3, c).
- Combined Pinching motion
At the heart of the motion space, on the common denominator of Apposition-Opposition, are the Neutral posture of the hand at rest (2b) and, near the clenching border, the Pinch (1-2, b-c), symbolizing all pinching motions.
Gravity and Expressivity
The Neutral hand is at rest when the basal tension of extensors and flexors balances with the effect of gravity on its parts. In the Taxonomy the hand is shown pending freely from the hanging underarm. A neutral hand on a vertically raised underarm has a more closed shape: nearer to that of the Fist: the symbolic gesture for individual endeavor, winning a race, or social; more or less peaceful, protest.
Function and Expressivity
The Pinch serves as a precision grip while the Large Grasp prepares for power grips. To us precision- and powergrips find themselves on a scale and do not exclude each other but are, in the individual, 'bridged' by his or hers dexterity.
The Cup enables to contain water and invites to give alms while the Cage can hold small living creatures and hold and hide small objects.
The abducted hand in extension on a raised underarm can express Halt in an urgent or even aggressive way. The adducted extended hand on a hanging underarm, seems to express the complementary meaning: here I stand with empty hands (no hidden weapons).
Research
Our Stance, Objectives, Methods and Simulation description.
Motion illustrations
Animations, illustrations and explanations of essential motions: the two main motion boundaries, opposing motions and segment motions on joints.
People
Our four authors in short.
References
Authors and publications on hand rendering, modeling, anatomy, physiology, methodology etc..
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