Four Books on Human Proportion

Below in the shinboneoriginal: "schinbein", a 27th part.
Through the anklesoriginal: "knorren"; referring to the bony protrusions of the ankle (malleoli)., a 22nd part.
And the foot in front, a 15th part.

After that, I make the widths of the front-facing armoriginal: "fürsichtigen arms".

Under the earsoriginal: "oren"; in this context of the arm's width, Dürer likely refers to the point of the arm level with the ears, or the uppermost part of the shoulder joint., an 18th part.
Behind the elbow, a 21st part.
In front of the elbow, a 16th part.
Behind the joint of the handoriginal: "glenck der hand"; the wrist., a 25th part.
And the open hand, a 15th part.

After that, by the third line, I make the back-view manoriginal: "hinderwertigen man" wide between the armpitsoriginal: "achsen" a 4th part, and split the buttocks for him from below upwards an 8th part.
And make the heels behind a 24th part wide.

Thus, when I have now all lengths, thicknesses, and widths

orderly described and marked by the three upright lines, I then draw the figure with lines according to my best judgment—or, if I can have one, I place a well-proportioned person before me and draw the lines according to him; that is always better than being made according to one’s own imagination.

It is also especially to be noted, when one draws the lines of the man’s figure, how nature has made the man so masterfully, as if he were made of two pieces: the body set upon the thighs. On both sides from the hip area, a curve goes down around the belly, and likewise backward over the buttocks; this I then follow in the construction sketchoriginal: "auffreissen"; the technical process of drawing or laying out the proportions., as can be seen hereafter before your eyes in the side-view, front-view, and back-view images.

I designate this man with an A.