Our feet would look very different if we had never worn shoes. And not only from a purely aesthetic point of view: even the bones of our ankles are different from those of a human being who spends his entire youth barefoot. This is demonstrated by research conducted by a group of anthropologists from the University of Chicago, published in Journal of Anatomywhich analyzed in detail the differences in skeletal anatomy between Aboriginal populations who habitually walk barefoot and individuals who grew up using modern footwear, and which offers important clues to further study the evolution of human locomotion.
“The skeleton is thought to be something immutable, but the reality is that it constantly changes throughout life in response to our behaviors,” explains Zewdi Tsegai, professor of anatomy and organismal biology at the University of Chicago, one of the authors of the research. “We used this skeletal plasticity to try to understand how it varies from person to person, and then to use this information to study fossils and interpret the behaviors that shaped them.”
The work focused on the analysis of the talus, a fundamental bone of the ankle that supports the body weight and connects the leg to the foot. Using advanced high-resolution computed tomography scanning techniques, they analyzed bone specimens from individuals who grew up regularly wearing shoes, and indigenous people from cultures that continue to live barefoot for most of their lives. The researchers examined the trabecular bone, the complex internal spongy network structure that provides structural support and distributes physical loads at the skeletal level.
The results show marked differences in the internal architecture between those who have always worn shoes and those who have lived barefoot. The absence of footwear significantly modifies the way in which mechanical forces propagate during walking, pushing the bone tissue to reorient itself over the course of life to respond to different stresses. In the skeletons of people who grew up wearing shoes, the trabecular bone is more concentrated within the talus, towards the big toe, suggesting greater weight distribution during walking towards the back of the bone. The natives, on the other hand, had a greater density of trabecular bone towards the front of the talus, suggesting completely different movement dynamics and stresses.
By studying such differences, in the future researchers believe it will be possible to better understand the clues contained in the fossil skeletons of our hominid ancestors, and deepen our understanding of the evolutionary processes that led to bipedalism. “Discovering anatomical variations within our modern species means that even the small differences we see in fossils have meaning,” explains Tsegai. “And if we connect behaviors in living humans with the structure of their bones, then we can look back and infer their behaviors and how bipedalism evolved.”