Royal Collection (RLW), 19009r; K/P 143r
These drawings illustrate a series of dissections of successive layers of the hand, down to the bones, with details highlighting the major and most complex joints. Applying his customary method, Leonardo depicts the muscles as strings or cords ("make strings instead of muscles") to indicate their lines of mechanical action. This enables him to demonstrate movements such as the opening, closing, and rotation of the hand, convergence, connection, and separation of the fingers, flexion and extension of the phalanxes, and so on.
Leonardo also clearly depicts the muscles that govern the independent movements of the thumb and little finger. The complex mechanics of the hand's many movements fascinated him.
.................................
|