The modern human skeleton is unique in the animal kingdom, having key differences from other primates. Millions of years ago, our primate ancestors changed their lifestyle from tree-bound primates to hunters who ran and chased game, which required a different anatomy. The human skeleton has an S-shaped spine (rather than curved), an upright pelvis, long legs, and arched feet for a lifetime of walking upright. This has many advantages, though it is known to put a lot of wear and tear on the spine. A lifetime of walking upright means fighting gravity acutely, and this results in frequent back problems …