If you have ever traveled to other countries around the world, you may have seen women carrying all sorts of things on THEIR heads. this is quite common in countries in South America and Africa. I even saw a man carrying a table on his head that could fit ten people around it when I was in Haiti. Most young girls learn this technique from THEIR mothers. When they are small children they practice balancing small objects on their heads. By the time they are young women, they can usually carry up to 25 percent of their body weight without using any energy at all. This is possible because of THEIR posture control. They form a line between THEIR vertebrae and pelvis. They USUALLY do not move THEIR head and shoulders around. These women can carry more weight (relative to body size) than pack mules. We Americans have all sorts of back problems because of the WEIGHT we carry on our backs. WE should really learn from them.
"Mayan Indian woman carrying basket on her head" by Robert Crum