Way back in our history, something shifted to give our distant ancestors a greater advantage. We started to walk on 2 legs exclusively, gaining the ability to use our hands separately from our feet.
What caused the shift? We can’t say, but we look at chimpanzees and other close relatives to observe their bipedal activity.
Chimps and other hominids typically don’t walk on two legs for long periods of time. However, they will use a two-legged stance to reach for food. As species adapt to swinging between branches, the body changes and adapts to demands placed on it by a new posture (Sylvester, 2006).
Similarly, for us, morphological changes over time (use-patterns, biomechanical efficiency, mutation or other factors) were almost certainly part of our adaption process. All told, this wasn’t a short series of simple “steps” to bipedalism. It was a long stumbling road with fits and starts that led to the first bipedal ape, or humans. (Preuschoft, 2004).
Humans are known for their creativity and ingenuity. If we imagine early humans, we think of animals that constantly recognized potential in their environment. They developed new tools, tried new things, figured things out.
Once we began walking upright, all of our load was focused onto 2 points – our feet. Not only that, but we began to cover all types of terrain. It probably wasn’t long before we figured out that we could reduce injuries from sharp sticks, rocks or other natural features by covering our feet.
Evidence shows that the use of footwear goes as far back as 24,000 years. One researcher provides a very good, if highly technical, overview of the effects of footwear on the foot – primarily on the increase of the arch and the decrease in the robustness of the big toe, especially of the lateral foot. The evolution of the modern foot is related to the use of footwear. This process continues to a very large extent with the advent of the modern “running shoe” with its over-sized wedge heel (Trinkaus, E., 2005).