I will point out this important matter later. After testing several graphic re­pro­duc­tions, I resolved to rely on ra­di­o­graphs, certainly not all the sa­me, but not invented. Some are very re­spon­sive, thus con­firm­ing what I have described. But considering for a while just one pictorial theme, the su­per­im­posed dark image may be ques­tion­able due to the lacking length of the arms (longer and shorter ones exist), but proves to have re­spect­ed the length of the limbs in their angles of rotation. A silent message?

It should begun to be not­ed that when the arm is ro­tat­ed up­wards, the ar­tic­u­la­tion ful­crum is also raised.
By the way, the na­vel's po­si­tion – that is not the cen­ter of grav­i­ty – could vary from the stand­ing to the su­pine pos­ture, as well as ac­cord­ing to the arms ex­ten­sion, hor­i­zon­tal or up­ward­ly,
if it fol­lows the stretch­ing of skin and mus­cles.