Bologna study: Neanderthal heels from 3D scans point to flat feet adapted for stability
Researchers compared heel bones of 7 Neanderthals and 64 Homo sapiens using 3D geometric morphometry. The Neanderthal heel was shorter, wider and taller.
A team from the University of Bologna and the IRCCS Rizzoli Orthopaedic Institute has published in the Journal of Human Evolution the first three-dimensional analysis of the external shape of the entire Neanderthal heel, according to eurekalert.org eurekalert.org
eurekalert.orgeurekalert.orgOpen source ↗. The researchers compared the heels of 7 Homo neanderthalensis individuals with those of 64 Homo sapiens. The authors conclude that Neanderthals most likely had flat feet, and describe this as a functional strategy to reduce impact stress under heavy loads and to maximize stability on mountainous or rough terrain, not as a defect.
Sample and method
The Homo sapiens group ranged from Pleistocene hunter-gatherers to Iron Age farmers and a post-industrial urban population from the Documented Human Osteological Collection of the Certosa Cemetery of Bologna. The team applied 3D geometric morphometry to digital models obtained with laser scans and computed tomography.
The work was led by Rita Sorrentino, now a professor at the University of Palermo, and coordinated by Professor Maria Giovanna Belcastro of the University of Bologna. The team also included researchers from the university's Department of Cultural Heritage and Department of Industrial Engineering, and from the motion analysis laboratory of the Rizzoli Institute.
Heel shape and foot posture
Compared with modern humans, Neanderthal heels were shorter, wider and taller eurekalert.org
eurekalert.orgeurekalert.orgOpen source ↗. Geometric analysis indicates that Neanderthals habitually showed foot pronation. The study also found a lower lateral longitudinal arch, which gave greater flexibility and mobility in the central part of the foot.
According to Belcastro, the robust heel reflects the overall build of Neanderthals, with considerable muscle and bone mass and a very high level of physical activity. She says these traits indicate adaptation for greater load-bearing capacity at the back of the foot and high mobility on uneven ground.
Comparison with Homo sapiens
Prehistoric Homo sapiens hunter-gatherers, who covered long distances barefoot or in soft footwear, had heels whose robustness was closer to that of Neanderthals than to that of modern post-industrial populations. People of recent centuries have much weaker heels, which the authors attribute to a sedentary lifestyle and habitual use of rigid, closed footwear.
The researchers note that shoes with rigid soles tend to limit inversion and eversion of the foot and tighten the ankle. They regard this as a sign of skeletal gracilization caused by a sharp reduction in natural biomechanical stimuli eurekalert.org
eurekalert.orgeurekalert.orgOpen source ↗. In Belcastro's words, skeletal morphology is the product not only of a genetic program but also of physical stimuli and daily habits.
