Dissecting Leonardo's Anatomy
 

The Shoulder The Arm The Hand

The Shoulder, Arm, and Hand         On depicting the shoulder: "Describe each muscle, what finger it serves and what limb; represent it therefore simply, without any impediment from any other muscle that is  placed over them, and in this way you will afterwards be able to recognise the parts which are injured. You will never know the shape of the shoulder without this rule" (qtd. in MacCurdy 101). On the composition of the hand and fingers: "Have you noted here the diligence of Nature in having placed the nerves, arteries and veins at the sides of the fingers and not in the middle, so that in operation of the fingers they do not in some way get pierced or cut?" (qtd. in Keele 528).     On arrangement of the drawings: "Make here first the simple bones, then cloth them gradually stage by stage in the same way that nature clothes them" (qtd. in MacCurdy 109).         On the function of the arm: "The arm, which has the two bones that interpose between the hand and the elbow, will be somewhat shorter when the palm of the hand is turned towards the ground than when it is turned towards the sky, if the man is standing on his feet with his arm extended. And this occurs because these two bones, in turning the palm of the hand towards the ground, come to intersect in such a way that that which proceeds from the right side of the elbow goes towards the left side of the palm of the hand, and that which proceeds from the left side of elbow ends on the right side of the palm of this hand" (qtd. in MacCurdy  94).                     On the composition of the hand and fingers: "Have you noted here the diligence of Nature in having placed the nerves, arteries and veins at the sides of the fingers and not in the middle, so that in operation of the fingers they do not in some way get pierced or cut?" (qtd. in Keele 528).