To create a manifest of his liking for the centuries to come, it would have done better to avoid retrofit with numerical tables and meticulous proportions, for Vitruvius not even neglected the finger tips! and with good reason: (please, click and watch what these images suggest about Phi, which mean the Golden Ratio was decidedly unknown to Vitruvius:)
"The architect Vitruvius says in his work about architecture that the measures of the human body are divided by nature as follows: 4 fingers constitute one hand width, 4 widths of a hand constitute one foot, 6 widths of a hand constitute one fore arm or yard, 4 yards constitute the height of a man. And 4 yards constitute a pace en 24 widths of a hand a man's height; and these measures he used for constructing buildings."
In fact, the contour annotations by Leonardo to the figure do nothing but simulate a semblance of modularity of a project which has no valid foundation, being based on approximation and compromised distortions. Any artful adaptation, above all if it not appropriate to the Creation Reality, might result misleading instead.Like for the arms' positions, Vitruvius didn't mention opened legs anyhow, but simply ‘extended hands and feet’, i.e. in normal mode, just oriented towards the outside, so that a circumference centered on the navel would touch toes and fingers; while it must be borne in mind that this cannot take place with every positioning angle of the limbs, although in lack of specifications by the architect. Which posture is right then?