We can model the human back as a pivoted rod?

So the answer is yes, we can the back be shaped like a spinning rod

spinal column that is approximated by a long and narrow rod,

Explanation:

The bone system of the body is very well modeled in physics, the back has a spinal column that is approximated by a long and narrow rod, this rod is fixed in the lower part to the coccyx and has a weight in the upper part (head), this rod has longitudinal vertical movement and twisting movement around the lower part of the bar.

So the answer is yes, we can the back be shaped like a spinning rod

the answer is kevlar