It is obvious to all that the human hand
represents a mechanism of the most intricate
fashioning and one of great complexity and
utility. But beyond this it is intimately correlated
with the brain, both in the evolution of
the species and in the development of the individual.
Hence, to a degree we "think" and
"feel" with our hands, and, in turn, our hands
contribute to the mental processes of thought
and feeling.
In any mechanism, animate or inanimate,
functional capabilities relate both to structural
characteristics and to the nature of the control
system available for management of functions
singly or in multiple combinations. Just
so with the human hand. Analysis of normal
hand characteristics therefore requires an
understanding of both sensory and mechanical
features. Of course whole volumes have been
written on hand anatomy, and it is not possible
in a short article to describe all elements
in detail. It is helpful, however, to review the
basic construction of bones and joints and of
the neuromuscular apparatus for governing
motions and forces. Twenty-four muscle
groups, controlled by the various motor and
sensory nerve pathways, with their rich potentialities
for central connection, and acting
upon a bone and joint system of great mechan-