How shoes change our bones—and what that tells us about the evolution of walking

A new study from the University of Chicago has revealed how our shoes can alter the structure of our bones. Researchers compared ankle bones from individuals who typically wear shoes to those who go barefoot and found significant differences in the internal structures of their skeletons. Assistant Professor Zewdi Tsegai, senior author of the study, explained that bones are not fixed structures; they constantly change throughout a person's life in response to their behavior.

To investigate this, the team focused on trabecular bone, the spongy tissue inside the ends of bones. This type of bone changes its internal structure to provide support and absorb shock, depending on the physical forces it experiences from activities like walking, running, and climbing. The researchers used high-resolution micro-CT scanning to analyze ankle bones from a group of 40 people who regularly wear shoes, and a group of 13 habitually barefoot skeletons from the Andaman Islands, two from southern Africa, and one from Central Africa.

They discovered that individuals who wear shoes have more trabecular bone at the back and inside of their talus bone, suggesting that shoes cause people to put more weight on these areas. On the other hand, barefoot individuals had more trabecular bone at the front of the talus, indicating that they place more weight on the bone from behaviors such as climbing or squatting.

These findings provide valuable reference points for understanding the evolution of walking in our fossil ancestors. By examining the variations in bone structure among living humans who engage in different behaviors, researchers can make inferences about the behavior and evolution of bipedalism in ancient humans.