Here are some comparison pictures regarding the Woman and Boy from the
Altgens photo. In the first, there is a big strong man holding a little
girl with one arm. She is sitting on his arm, and in order to be facing
straight, she's got her spine twisted- a lot.
http://img835.imageshack.us/img835/8130/h8b5.jpg
Note that you can see the man's arm underneath the girl. You can't see the
woman's arm underneath the boy. And note that since the girl is
essentially sitting, you can see her legs projecting in front of her
torso. But you can't see the legs of the boy, and that's because they are
underneath him; he's standing.
Then, there is this image of a girl being held by a woman who is not a big
strong man, so she has to use a different technique. She essentially has
the girl sitting on and straddling her pelvic bone. That relieves her arms
of the work of holding her up. So, it transfers the weight to the woman's
legs, which are relatively much stronger. There is much less disparity in
leg strength between men and women than for arm strength. But, in order to
get it to work, she has a V going. The V refers to her leaning the girl
out slightly away from her and leaning herself the other way.
http://img580.imageshack.us/img580/7643/yl6m.jpg
The V is very effective because it gets a counterbalance going.
Counterbalance is, of course, what enables two children to both remain
suspended in the air on a seesaw without expending any energy. In this
case, the leaning takes the woman's muscles to the point of tensile
stretch- where they are operating more like straps than muscles. This
conserves energy.
But, on the Woman and Boy from Altgens both are vertical; there is no
leaning going on. She is getting none of the energy savings. If she is
supporting him with her arm, she's doing it through active contraction and
nothing else. Superwoman!
Then, here is another very common way of holding a child: leaning
backwards. What that does is exploit the tensile strength of the extensor
muscles and ligaments of the back, and also the tensile strength of the Y
ligament of Bigelow, also known as the iliofemoral ligament, which is the
strongest ligament in the humn body. Tensile strength refers to resistance
to being stretched, not active contraction. So, it doesn't cost any
energy; you're just leaning on the ligament. It is NOT the correct way to
carry anything, but people often do it. It's really a form of laziness as
far as I'm concerned. But notice that this is a man doing it, not a woman.
Also notice that the child he is holding is smaller and lighter than the
boy in the Altgens photo.
http://img94.imageshack.us/img94/5976/1g3d.jpg
Just compare the two. Does anybody still think that she is holding up that
boy? She most certainly is not.