The bones, muscles and tendons of the hand
© Mark Mobley, West Midlands Surgical Training Centre, UHCW Trust, 2013
Leonardo’s skills as an anatomist are displayed to perfection in his investigation of the hand (as shown below). A meticulous technique was required to dissect out these small-scale structures. His experience as an engineer led him to appreciate the layering and interaction of the different systems and his skill as a draughtsman allowed him to convey his findings in illustrations that have rarely been equalled.
Above is a 3D film of a hand, dissected and then plastinated by the impregnation of a setting polymer to preserve the fine detail of the soft tissues.
The flexor tendons have been lifted away from the fingers to show the deeper tendon passing through a split in the superficial tendon and attaching towards the fingertip, thus effecting the curling of the finger.
Leonardo was entranced by the elegance of this arrangement. Surrounding a detailed drawing of the feature, he wrote of his proposed treatise:
‘Provide that the chapter on the elements of mechanics comes before the demonstration of the movement and force of man … and thereby you will be able to prove all your propositions.’
The drawings on this sheet demonstrate with complete clarity the structure of the hand, building it up in the manner of an engineer.
Leonardo begins with the bones, then adds the deep muscles of the palm at lower right, and the first and second layers of tendons at upper left and upper right. Anatomists today use exactly the same sequence of images when trying to understand the hand and the animated computer simulation above replicates the artist’s layering technique.
Within the fingers, the deeper tendon penetrates the more superficial: Leonardo was entranced by the elegance of this arrangement, as shown in the detail at upper centre.
