I will eventually go into more detail later, but here is an introduction to this topic.
Our ability to stand and ambulate on two legs is arguably THE thing which makes us human, and certainly separates us from our primate cousins. I believe our ancestors’ move toward bipedality went hand in hand, so to speak, with our desire or need to carry things from place to place.
It is helpful to understand this if one wants to perform tasks involving bipedality-walking, running, even standing-efficiently and comfortably.
Perhaps imagine the types of things early hominids may have carried. What would be the most comfortable way to hold such objects for relatively long periods? Understanding this can help us function better as a two-legged creature, I believe.