A picture of an infant reaching down to pick something up, note that his head is not pulled back but extends outwards along the path of his spine, an adult will often show a distinct kink in the neck when performing a similar pick up gesture.
How easily we can corrupt the essential head-neck-back relationship when picking something up from the floor, note how the infant effortlessly preserves the integrity of his head-neck-back relationship and so keeps optimal strength and flexibility in his spine. This is not as simple as an analysis of shape, it runs deeper than that, its…