In his research, Lieberman used a high-speed video to analyze 23 people, 13 who wore huaraches and 10 who used running shoes. They ran at 7:30 minute/mile paces so that they could observe their foot strikes, stride lengths, arch structure, hip, knee, and ankle movements.
They found a lot of variations in foot strike patterns, finding that the Tarahumara people had stiffer arches, high step frequency, and little to no overstride. Research shows that stiff arches could lead to fewer injuries and a more efficient energy return. Some people believe that indigenous people like the Tarahumara are built differently because they live out in the country where they walk everywhere and for long distances. That they are built differently than other people that are used to conventional running shoes, perhaps they are right, but nonetheless, it’s still quite fascinating.